The kidneys are two fist sized organs located in the abdomen toward the back, normally one on each side of the spine.
The main function of the kidneys is to remove waste products and excess water from the blood. The kidneys process about 200 liters of blood every day to produce about two to three liters of urine.
The kidneys also produce certain hormones that have important functions in the body, including the active form of vitamin D, which regulates absorption of calcium and phosphorus from foods, erythropoietin (EPO), which stimulates the bone marrow to produce red blood cells and Renin, which regulates blood volume and blood pressure.
With loss of kidney function, there is an accumulation of water, waste and toxic substances in the body, that are normally excreted by the kidney.
Loss of kidney function also causes other problems such as anemia, high blood pressure, metabolic acidosis, disorders of cholesterol and bone disease.
Kidney Injury may be acute or chronic.
Acute kidney injury develops rapidly, over days or weeks and usually develops in response to a disorder that directly affects the kidney, its blood supply, or urine flow from it. Acute kidney injury is often reversible, with complete recovery of kidney function although it may progress to Chronic kidney disease.
Chronic kidney disease occurs when one suffers from gradual and usually permanent loss of kidney function over time. This happens gradually, usually months to years although it may happen more rapidly too. Chronic kidney disease is divided into five stages(stage 1 to stage 5) of increasing severity, with stage 5 being the stage where the patient needs renal replacement therapy.
Causes of Chronic kidney disease include:
- Diabetes mellitus causes a condition called diabetic nephropathy, which is the leading cause of kidney disease.
- Hypertension, especially if not well controlled, is the second most important cause of chronic kidney disease and can damage the kidneys over time.
- Glomerulonephritis, which can occur due to a mumber of causes, can damage the kidneys which may eventually lead to kidney failure. The most common of this is a condition called IgA nephropathy.
Polycystic kidney disease is a hereditary cause of chronic kidney disease where in both kidneys have multiple cysts which grow over time and eventually lead to renal failure.
Use of analgesics (pain killer medicines) regularly over long durations of time can cause analgesic nephropathy, another cause of kidney disease. Certain other medications can also damage the kidneys.
Clogging (atherosclerosis) and hardening of the blood vessels of the kidneys causes a condition called ischemic nephropathy, which is another cause of progressive kidney damage.
Obstruction of the flow of urine by stones, an enlarged prostate, strictures, or cancer may also cause kidney disease.
Vesicoureteric reflux (a urinary tract problem in which urine travels the wrong way back toward the kidney) is a common cause of chronic kidney disease in children and young adults.
Effects and symptoms of chronic kidney disease include:
- Increased frequency of urination, especially at night.
- Swelling of the legs and puffiness around the eyes (fluid retention).
- High blood pressure.
- Fatigue and weakness (from anemia or accumulation of waste products in the body.
- Loss of appetite, nausea and vomiting.
- Low hemoglobin levels.
- Shortness of breath from fluid accumulation in the lungs and metabolic acidosis.
- Bone pains and increased risk of fractures.
Chronic kidney disease usually causes no symptoms in its early stages. Only lab tests can detect any developing problems. Anyone at increased risk for chronic kidney disease should be routinely tested for development of this disease.
Urine, blood, and imaging tests such as ultrasound are used to detect kidney disease, as well as to follow its progress.
Kidney disease is usually advanced by the time symptoms appear. If you are at high risk of developing chronic kidney disease, see your Nephrologist (kidney specialist) for screening tests.
Strategies for slowing progression and treating conditions underlying chronic kidney disease include the following:
- Control of blood glucose: Maintaining good control of diabetes is critical. People with diabetes who do not control their blood glucose have a much higher risk of all complications of diabetes, including chronic kidney disease. This has been established in well known trials such as the DCCT trial and the UKPDS study as well in a number of other trials.
- Control of high blood pressure: This is extremely important to slow progression of chronic kidney disease both in diabetics as well as non diabetic patients with kidney disease. It is recommended to keep your blood pressure below 130/80 mm Hg if you have kidney disease. Blood pressure medications known as Angiotensin converting enzyme (ACE) inhibitors or Angiotensin receptor blockers (ARB) have special benefit in protecting the kidneys.
- Avoid exposure to kidney unfriendly drugs especially NSAIDs (pain killer medications), chemicals, and other toxic substances as much as possible.
- Watch your weight! People who are very obese are at higher risk of chronic kidney disease.
- Avoid smoking. Smoking has been found to increase the risk of progression of kidney disease.