What are the stages of kidney disease?

Your GFR is the best indicator of how well your kidneys are working. In 2002, the National Kidney Foundation published treatment guidelines that identified five stages of CKD based on declining GFR measurements. The guidelines recommend different actions based on the stage of kidney disease.

• Increased risk of CKD. A GFR of 90 or above is considered normal. Even with a normal GFR, you may be at increased risk for developing CKD if you have diabetes, high blood pressure, or a family history of kidney disease. The risk increases with age: People over 65 are more than twice as likely to develop CKD as people between the ages of 45 and 65. African Americans also have a higher risk of developing CKD.
  
  
• Stage 1: Kidney damage with normal GFR (90 or above). Kidney damage may be detected before the GFR begins to decline. In this first stage of kidney disease, the goals of treatment are to slow the progression of CKD and reduce the risk of heart and blood vessel disease.
  
  
• Stage 2: Kidney damage with mild decrease in GFR (60 to 89). When kidney function starts to decline, your health care provider will estimate the progression of your CKD and continue treatment to reduce the risk of other health problems.
  
  
• Stage 3: Moderate decrease in GFR (30 to 59). When CKD has advanced to this stage, anemia and bone problems become more common. Work with your health care provider to prevent or treat these complications.
  
  
• Stage 4: Severe reduction in GFR (15 to 29). Continue following the treatment for complications of CKD and learn as much as you can about the treatments for kidney failure. Each treatment requires preparation. If you choose hemodialysis, you will need to have a procedure to make a vein in your arm larger and stronger for repeated needle insertions. For peritoneal dialysis, you will need to have a catheter placed in your abdomen. Or you may want to ask family or friends to consider donating a kidney for transplantation.
  
  
• Stage 5: Kidney failure (GFR less than 15). When the kidneys do not work well enough to maintain life, you will need dialysis or a kidney transplant.
  
  

In addition to tracking your GFR, blood tests can show when substances in your blood are out of balance. If phosphorus or potassium levels start to climb, a blood test will prompt your health care provider to address these issues before they permanently affect your health.

How do kidneys fail?

Many factors that influence the speed of kidney failure are not completely understood. Researchers are still studying how protein in the diet and cholesterol levels in the blood affect kidney function.

Acute Renal Failure

Some kidney problems happen quickly, like an accident that injures the kidneys. Losing a lot of blood can cause sudden kidney failure. Some drugs or poisons can make your kidneys stop working. These sudden drops in kidney function are called acute renal failure (ARF).

ARF may lead to permanent loss of kidney function. But if your kidneys are not seriously damaged, acute renal failure may be reversed.

Chronic Kidney Disease

Most kidney problems, however, happen slowly. You may have “silent” kidney disease for years. Gradual loss of kidney function is called chronic kidney disease (CKD) or chronic renal insufficiency. People with CKD may go on to permanent kidney failure. They also have a high risk of dying from a stroke or heart attack.

End-Stage Renal Disease

Total or nearly total and permanent kidney failure is called end-stage renal disease (ESRD). People with ESRD must undergo dialysis or transplantation to stay alive.

Why do kidneys fail?

Most kidney diseases attack the nephrons, causing them to lose their filtering capacity. Damage to the nephrons may happen quickly, often as the result of injury or poisoning. But most kidney diseases destroy the nephrons slowly and silently. Only after years or even decades will the damage become apparent. Most kidney diseases attack both kidneys simultaneously.

The two most common causes of kidney disease are diabetes and high blood pressure. If your family has a history of any kind of kidney problems, you may be at risk for kidney disease.

Diabetic Nephropathy

Diabetes is a disease that keeps the body from using glucose (sugar) as it should. If glucose stays in your blood instead of breaking down, it can act like a poison. Damage to the nephrons from unused glucose in the blood is called diabetic nephropathy. If you keep your blood glucose levels down, you can delay or prevent diabetic nephropathy.

High Blood Pressure

High blood pressure can damage the small blood vessels in your kidneys. The damaged vessels cannot filter wastes from your blood as they are supposed to.

Your doctor may prescribe blood pressure medication. Blood pressure medicines called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) have been found to protect the kidneys even more than other medicines that lower blood pressure to similar levels. The National Heart, Lung, and Blood Institute (NHLBI), one of the National Institutes of Health, recommends that people with diabetes or reduced kidney function should keep their blood pressure below 130/80 mm Hg.

Glomerular Diseases

Several different types of kidney disease are grouped together under this category, including autoimmune diseases, infection-related diseases, and sclerotic diseases. As the name indicates, glomerular diseases attack the tiny blood vessels (glomeruli) within the kidney. The most common primary glomerular diseases include membranous nephropathy, IgA nephropathy, and focal segmental glomerulosclerosis. Protein, blood, or both in the urine are often the first signs of these diseases. They can slowly destroy kidney function. Blood pressure control is important with any kidney disease. Treatments for glomerular diseases may include immunosuppressive drugs or steroids to reduce inflammation and proteinuria, depending on the specific disease.

Inherited and Congenital Kidney Diseases

Some kidney diseases result from hereditary factors. Polycystic kidney disease (PKD), for example, is a genetic disorder in which many cysts grow in the kidneys. PKD cysts can slowly replace much of the mass of the kidneys, reducing kidney function and leading to kidney failure.

Some kidney problems may show up when a child is still developing in the womb. Examples include autosomal recessive PKD, a rare form of PKD, and other developmental problems that interfere with the normal formation of the nephrons. The signs of kidney disease in children vary. A child may grow unusually slowly, may vomit often, or may have back or side pain. Some kidney diseases may be “silent” for months or even years.

If your child has a kidney disease, your child’s doctor should find it during a regular checkup. Be sure your child sees a doctor regularly. The first sign of a kidney problem may be high blood pressure, a low number of red blood cells (anemia), or blood or protein in the child’s urine. If the doctor finds any of these problems, further tests may be necessary, including additional blood and urine tests or radiology studies. In some cases, the doctor may need to perform a biopsy—removing a tiny piece of the kidney to examine under a microscope.

Some hereditary kidney diseases may not be detected until adulthood. The most common form of PKD was once called "adult PKD" because the symptoms of high blood pressure and renal failure usually do not occur until patients are in their twenties or thirties. But with advances in diagnostic imaging technology, doctors have found cysts in children and adolescents before any symptoms appear.

Other Causes of Kidney Disease

Poisons and trauma, for example a direct and forceful blow to your kidneys, can lead to kidney disease.

Some over-the-counter medicines can be poisonous to your kidneys if taken regularly over a long period of time. Products that combine aspirin, acetaminophen, and other medicines such as ibuprofen have been found to be the most dangerous to the kidneys. If you take painkillers regularly, check with your doctor to make sure you are not putting your kidneys at risk.

What do my kidneys do?

The kidneys remove wastes and extra water from the blood to form urine. Urine flows from the kidneys to the bladder through the ureters.

Your kidneys are bean-shaped organs, each about the size of your fist. They are located near the middle of your back, just below the rib cage. The kidneys are sophisticated reprocessing machines. Every day, your kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water. The waste and extra water become urine, which flows to your bladder through tubes called ureters. Your bladder stores urine until you go to the bathroom.

The wastes in your blood come from the normal breakdown of active tissues and from the food you eat. Your body uses the food for energy and self-repair. After your body has taken what it needs from the food, waste is sent to the blood. If your kidneys did not remove these wastes, the wastes would build up in the blood and damage your body.

The actual filtering occurs in tiny units inside your kidneys called nephrons. Every kidney has about a million nephrons. In the nephron, a glomerulus—which is a tiny blood vessel, or capillary—intertwines with a tiny urine-collecting tube called a tubule. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system.

At first, the tubules receive a combination of waste materials and chemicals that your body can still use. Your kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, your kidneys regulate the body’s level of these substances. The right balance is necessary for life, but excess levels can be harmful.

[d]

In the nephron (left), tiny blood vessels intertwine with urine-collecting tubes. Each kidney contains about 1 million nephrons.

In addition to removing wastes, your kidneys release three important hormones:

• erythropoietin (eh-RITH-ro-POY-eh-tin), or EPO, which stimulates the bone marrow to make red blood cells
  
  
• renin (REE-nin), which regulates blood pressure
  
  
• calcitriol (kal-suh-TRY-ul), the active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body

What medical tests will my doctor use to detect kidney disease?

Since you can have kidney disease without any symptoms, your doctor may first detect the condition through routine blood and urine tests. The National Kidney Foundation recommends three simple tests to screen for kidney disease: a blood pressure measurement, a spot check for protein or albumin in the urine (proteinuria), and a calculation of glomerular filtration rate (GFR) based on a serum creatinine measurement. Measuring urea nitrogen in the blood provides additional information.

Blood Pressure Measurement

High blood pressure can lead to kidney disease. It can also be a sign that your kidneys are already impaired. The only way to know whether your blood pressure is high is to have a health professional measure it with a blood pressure cuff. The result is expressed as two numbers. The top number, which is called the systolic pressure, represents the pressure when your heart is beating. The bottom number, which is called the diastolic pressure, shows the pressure when your heart is resting between beats. Your blood pressure is considered normal if it stays below 120/80 (expressed as “120 over 80”). The NHLBI recommends that people with kidney disease use whatever therapy is necessary, including lifestyle changes and medicines, to keep their blood pressure below 130/80.

Microalbuminuria and Proteinuria

Healthy kidneys take wastes out of the blood but leave protein. Impaired kidneys may fail to separate a blood protein called albumin from the wastes. At first, only small amounts of albumin may leak into the urine, a condition known as microalbuminuria, a sign of deteriorating kidney function. As kidney function worsens, the amount of albumin and other proteins in the urine increases, and the condition is called proteinuria. Your doctor may test for protein using a dipstick in a small sample of your urine taken in the doctor’s office. The color of the dipstick indicates the presence or absence of proteinuria.

A more sensitive test for protein or albumin in the urine involves laboratory measurement and calculation of the protein-to-creatinine or albumin-to-creatinine ratio. This test should be used to detect kidney disease in people at high risk, especially those with diabetes. If your first laboratory test shows high levels of protein, another test should be done 1 to 2 weeks later. If the second test also shows high levels of protein, you have persistent proteinuria and should have additional tests to evaluate your kidney function.

Glomerular Filtration Rate (GFR) Based on Creatinine Measurement

GFR is a calculation of how efficiently the kidneys are filtering wastes from the blood. A traditional GFR calculation requires an injection into the bloodstream of a substance that is later measured in a 24-hour urine collection. Recently, scientists found they could calculate GFR without an injection or urine collection. The new calculation requires only a measurement of the creatinine in a blood sample.

Creatinine is a waste product in the blood created by the normal breakdown of muscle cells during activity. Healthy kidneys take creatinine out of the blood and put it into the urine to leave the body. When kidneys are not working well, creatinine builds up in the blood.

In the lab, your blood will be tested to see how many milligrams of creatinine are in one deciliter of blood (mg/dL). Creatinine levels in the blood can vary, and each laboratory has its own normal range, usually 0.6 to 1.2 mg/dL. If your creatinine level is only slightly above this range, you probably will not feel sick, but the elevation is a sign that your kidneys are not working at full strength. One formula for estimating kidney function equates a creatinine level of 1.7 mg/dL for most men and 1.4 mg/dL for most women to 50 percent of normal kidney function. But because creatinine values are so variable and can be affected by diet, a GFR calculation is more accurate for determining whether a person has reduced kidney function.

The new GFR calculation uses the patient’s creatinine measurement along with weight, age, and values assigned for sex and race. Some medical laboratories may make the GFR calculation when a creatinine value is measured and include it on their lab report.

Blood Urea Nitrogen (BUN)

Blood carries protein to cells throughout the body. After the cells use the protein, the remaining waste product is returned to the blood as urea, a compound that contains nitrogen. Healthy kidneys take urea out of the blood and put it in the urine. If your kidneys are not working well, the urea will stay in the blood.

A deciliter of normal blood contains 7 to 20 milligrams of urea. If your BUN is more than 20 mg/dL, your kidneys may not be working at full strength. Other possible causes of an elevated BUN include dehydration and heart failure.

Additional Tests for Kidney Disease

If blood and urine tests indicate reduced kidney function, your doctor may recommend additional tests to help identify the cause of the problem.

Chronic kidney failure

Chronic kidney failure is a slowly progressive decline (months to years) in the kidneys' ability to filter metabolic waste from the blood.

Many diseases can irreversibly damage or injure the kidneys. Acute kidney failure can become chronic if kidney function does not recover after treatment. Therefore, anything that can cause acute kidney failure can cause chronic kidney failure. However, the most common cause of chronic kidney failure is diabetes mellitus, followed by high blood pressure (hypertension). Both of these conditions directly harm the kidneys' small blood vessels. Other causes of chronic kidney failure include urinary tract obstruction; kidney abnormalities (such as polycystic kidney disease and glomerulonephritis); and autoimmune disorders (such as systemic lupus erythematosus), in which antibodies damage the tiny blood vessels (glomeruli) and the tiny tubes (tubules) of the kidneys.

Symptoms

Symptoms may develop slowly or evolve from acute kidney failure. A person with mild to moderate kidney failure may have only mild symptoms despite the increase in the levels of urea and other metabolic waste products in the blood. At this stage, the person may need to urinate several times during the night (nocturia), because the kidneys cannot absorb water from the urine to reduce the volume and concentrate it as normally occurs during the night.

As kidney failure progresses and metabolic wastes build up in the blood, the person may feel fatigued and generally weak and may become less mentally alert. These symptoms progress as the blood becomes more acidic, a condition called acidosis. A loss of appetite and shortness of breath can result. Fatigue and generalized weakness may also be attributed in part to a decline in red blood cell production and the resulting anemia. People with chronic kidney failure tend to bruise easily or bleed for an unusually long time after cuts or other injuries. Chronic kidney failure also diminishes the body's ability to fight infections.

As metabolic wastes build up in the blood, damage to muscles and nerves can cause muscle twitches, muscle weakness, cramps, and pain. The person may also feel a pins-and-needles sensation in the arms and legs and may lose sensation in certain areas of the body. Encephalopathy, a condition in which the brain malfunctions, may ensue from the buildup of metabolic waste products in the blood. This condition may lead to confusion, lethargy, and seizures.

High blood pressure often develops in people who have kidney failure, because the diseased kidneys produce hormones that raise blood pressure. In addition, diseased kidneys cannot excrete excess salt and water. Salt and fluid retention can lead to heart failure, which may cause shortness of breath. The sac that surrounds the heart (pericardium) may become inflamed (pericarditis) as metabolic waste products accumulate. This complication may cause chest pain and low blood pressure. The level of triglycerides in the blood is often elevated, which, along with hypertension, increases the risk for atherosclerosis. The buildup of metabolic waste in the blood also causes nausea, vomiting, and an unpleasant taste in the mouth, which may lead to malnutrition and weight loss. People who have advanced chronic kidney failure commonly develop gastrointestinal ulcers and bleeding. The skin may turn yellow-brown, and occasionally, the concentration of urea is so high that it crystallizes from sweat, forming a white powder on the skin. Some people with chronic kidney failure itch all over their body.

The formation and maintenance of bone tissue may be impaired (renal osteodystrophy) if certain conditions that accompany chronic kidney failure are present for a long time. These conditions include a high level of parathyroid hormone, low concentration of calcitriolSome Trade Names
ROCALTROL
(the active form of vitamin D) in the blood, impaired absorption of calcium, and a high concentration of phosphate in the blood. Renal osteodystrophy may lead to bone pain and an increased risk of fractures.

Diagnosis

Blood tests are essential and show increased levels of urea and creatinine, metabolic waste products that are normally filtered out by the kidneys. Typically, the blood becomes moderately acidic. The level of potassium in the blood is normal or only slightly increased but can become dangerously high when kidney failure reaches an advanced stage or if a person ingests large amounts of potassium. Usually, the person has some decline in red blood cell count (anemia). The level of triglycerides in the blood is likely to be elevated. The calcium and calcitriolSome Trade Names
ROCALTROL
levels decrease, and the phosphate and parathyroid hormone levels increase.

Urine volume often stays about the same, regardless of the amount of fluid consumed. Analysis of the urine may detect many abnormalities, including protein and abnormal cells.

Determining a precise cause becomes increasingly difficult as the kidney failure reaches an advanced stage. A kidney biopsy may be the most accurate test, but it is not recommended if results of an ultrasound show that the kidneys are small and scarred.

Prognosis and Treatment

Ultimately, chronic kidney failure progresses in most people regardless of treatment. It is fatal if not treated. Survival when kidney failure is severe (sometimes called end-stage kidney failure) is usually limited to several months in people who are not treated, but those who are treated with dialysis can live many years. The doctor must pay attention to conditions that can cause or worsen kidney failure and consequences of the kidney failure that might adversely affect overall health. For example, infections are treated promptly with antibiotics, and any obstructions in the urinary tract are removed or relieved.

The rate of decline in kidney function depends somewhat on the underlying disorder causing the kidney failure. For example, controlling the level of sugar in the blood as well as hypertension in people with diabetes substantially slows deterioration in kidney function. Drugs called angiotensin-converting enzyme (ACE) inhibitors and also angiotensin receptor blockers may decrease the rate of decline in kidney function in some people with chronic kidney failure.

Meticulous attention to diet helps control a number of potential problems. Sometimes mild acidosis can be controlled by increasing the intake of carbohydrates and reducing proteins. However, moderate or severe acidosis may require treatment with sodium bicarbonate. The decline in kidney function can be slowed slightly by restricting the amount of protein consumed daily. The person needs to consume sufficient carbohydrates to offset the reduction in protein. The triglyceride level may be lowered somewhat by limiting fat in the diet. Drugs such as gemfibrozilSome Trade Names
LOPID
may be required to reduce the triglyceride level.

The intake of salt (sodium) usually does not have to be restricted unless fluid accumulates and is retained in the tissues or high blood pressure develops. A person with heart failure needs to restrict the intake of sodium. Diuretics may also relieve symptoms of heart failure, even when kidney function is poor, but dialysis may be needed to remove the excess fluid.

During chronic kidney failure, changes in thirst usually determine how much water is consumed. Occasionally, water intake needs to be restricted to prevent the sodium concentration in the blood from becoming too low. Foods that are extremely high in potassium, such as salt substitutes, must be avoided, and foods that are somewhat high in potassium, such as dates and figs, should not be consumed in excess. A high potassium level in the blood increases the risk of abnormal heart rhythms and cardiac arrest. If the potassium level becomes too high, drugs may help, but emergency dialysis may be required.

The elevated phosphorus level in the blood can cause deposits of calcium and phosphorus to form in tissues, including the blood vessels. Restricting the intake of foods high in phosphorus, such as dairy products, liver, legumes, nuts, and most soft drinks, lowers the phosphate concentration in the blood. Drugs that bind phosphate, such as calcium carbonateSome Trade Names
TUMS
CALTRATE
OSCAL
and calcium acetate, taken by mouth, may also lower the phosphorus level in the blood.

The anemia caused by kidney failure responds to the drugs erythropoietinSome Trade Names
EPOGEN
PROCRIT
or darbepoietin. Blood transfusions are given only if the anemia is severe, is causing symptoms, and does not respond to erythropoietinSome Trade Names
EPOGEN
PROCRIT
or darbepoietin. Doctors also look for and treat other causes of anemia, particularly dietary deficiencies of iron, folic acid (folate), and vitamin B₁₂ or excesses of aluminum in the body. Most people receiving erythropoietinSome Trade Names
EPOGEN
PROCRIT
or darbepoietin regularly need to be given iron intravenously to prevent iron deficiency, which impairs the body's response to these drugs. Anemia often requires more aggressive treatment in older people, because they are more likely to have heart disease, which can be aggravated by the anemia. The tendency to bleed can be temporarily suppressed by transfusions of platelets or fresh frozen plasma or by such drugs as desmopressinSome Trade Names
DDAVP
STIMATE
or estrogensSome Trade Names
PREMARIN
. Such treatment may be needed after an injury or before a surgical procedure or a tooth extraction.

A moderate or severe increase in blood pressure is treated with blood pressure drugs to prevent further impairment of heart and kidney function.

When the treatments for chronic kidney failure are no longer effective, the only option is long-term dialysis or kidney transplantation (see Transplantation: Kidney Transplantation). Despite the advent of dialysis, most people with advanced kidney failure die within 5 to 10 years. End-of-life care is important (see Death and Dying: Introduction).

Kidney Disease (High Blood Pressure Related) Glossary of Terms

ACE inhibitors : A drug that inhibits ACE (angiotensin converting enzyme) which is important to the formation of angiotensin II. Angiotensin II causes arteries in the body to constrict and thereby raises the blood pressure. ACE inhibitors lower the blood pressure by inhibiting the formation of angiotensin II. This relaxes the arteries. Relaxing the arteries not only lowers blood pressure, but also improves the pumping efficiency of a failing heart and improves cardiac output in patients with heart failure. ACE inhibitors are therefore used for blood pressure control and congestive heart failure .
See the entire definition of ACE inhibitors

Alcohol: An organic chemical in which one or more hydroxyl (OH) groups are attached to carbon (C) atoms in place of hydrogen (H) atoms. Common alcohols include ethyl alcohol or ethanol (found in alcoholic beverages), methyl alcohol or methanol (can cause blindness) and propyl alcohol or propanol (used as a solvent and antiseptic ). Rubbing alcohol is a mixture of acetone , methyl isobutyl ketone, and ethyl alcohol. In everyday talk, alcohol usually refers to ethanol as, for example, in wine, beer, and liquor. It can cause changes in behavior and be addictive.
See the entire definition of Alcohol

Angiotensin: A family of peptides (smaller than proteins) that act as vasoconstrictors to narrow blood vessels.

Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.

Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Caffeine: A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea.
See the entire definition of Caffeine

Creatinine: A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body's creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and dispose of it in the urine.
See the entire definition of Creatinine

Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus . Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
See the entire definition of Diabetes

Dialysis: The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood. Dialysis allows patients with kidney failure a chance to live productive lives. There are two types of dialysis: hemodialysis and peritoneal dialysis. Each type of dialysis has advantages and disadvantages. Patients can often choose the type of long term dialysis that best matches their needs.

Diastolic: Referring to the time when the heart is in a period of relaxation and dilatation (expansion).
See the entire definition of Diastolic

Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.

Diuretic: Anything that promotes the formation of urine by the kidney. (The word "diuretic" comes from a combination of the Greek "dia-", thoroughly + "ourein", to urinate = to urinate thoroughly).
See the entire definition of Diuretic

End-stage renal disease: ESRD. Chronic irreversible renal failure.

Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions , converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist.
See the entire definition of Enzyme

ESRD: End-stage renal disease.

Glomerular: Pertaining to the glomerulus, a tiny structure in the kidney that filters the blood to form urine.

Health: As officially defined by the World Health Organization, a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
See the entire definition of Heart

Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease. Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina; Arrhythmia; Congenital heart disease; Coronary artery disease (CAD); Dilated cardiomyopathy; Heart attack (myocardial infarction); Heart failure; Hypertrophic cardiomyopathy; Mitral regurgitation; Mitral valve prolapse; and Pulmonary stenosis.

High blood pressure : Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
See the entire definition of High blood pressure

Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
See the entire definition of Hypertension

Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.