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NetWellness provides the highest quality health information and education services created and evaluated by faculty of our partner universities.
Wednesday, July 9, 2008
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- What would cause protein in the urine?
- What would cause blood in the urine?
- Is edema associated with kidney disease?
- Where would I experience the pain associated with kidneys?
- Is anemia associated with kidney disease?
- Can kidney disease lead to hair loss?
- What is the association between hypertension and kidney disease?
The kidneys excrete protein in the urine when the membranes of the filtering system in the kidney have larger holes in them than normal. Each kidney is made up of thousands of filtering units, which normally do not permit large molecules like proteins to go through them. These filtering units are the start of urine formation. Once through these filters, the water and small molecules go to a tubular system that leads to the bladder. The tubular system is designed so that filtered material that needs to be saved is returned to the blood. Also, material that should be excreted that did not get through the filters is taken out of the blood and put into the tubular fluid. This is how the kidney keeps the right amount of sodium, water, glucose, and many other substances in the blood stream. Too much protein in the urine indicates that the filters are leaking. This may be due to high blood pressure, which is forcing the protein through the filters. Kidney diseases that affect the filtering membranes may also cause protein in the urine. If the protein is accompanied by high blood pressure, it could reflect secondary focal glomerulosclerosis.
There are many causes for blood in the urine that are due to the kidneys. If there is little to no protein in the urine associated with the blood, this suggests the bleeding might be from a cyst. If there is protein in the urine that suggests that there is involvement of the filtering membranes in the kidney. A common cause for blood in the urine is due to kidney stones. This is usually associated with severe pain.
Edema occurs with many different kidney diseases that involve the filtering membrane called the glomerular basement membrane. Such diseases usually have the prefix of glomerular (i.e.glomerulonephritis). The major cause of edema is losing the serum protein "Albumin". Albumin is a protein that helps to keep fluid in the blood stream and does not allow it to leak out of the capillaries into the surrounding tissues. When this leak does occur, edema results.
Usually, kidney pains are felt on one side or the other of the back, just to the right or left of the backbone and just below the last rib. Severe pain in this location accompanied by chills and fever may be indicative of a kidney infection.
Anemia is common in people with kidney disease. Healthy kidneys produce a hormone called erythropoietin (EPO), which stimulates the bone marrow to produce the proper number of red blood cells needed to carry oxygen to vital organs. Diseased kidneys, however, often don't make enough EPO. As a result, the bone marrow makes fewer red blood cells. It becomes obvious when more than 50% of the kidneys are not functioning. The degree of anemia associated with an elevated serum creatinine and blood urea nitrogen (BUN) help decide whether dialysis treatment is necessary. Other common causes of anemia include loss of blood from hemodialysis and low levels of iron and folic acid.
Hair loss caused by kidney disease is very unusual, and generally only seen with advanced kidney failure. If a person loses large amounts of the protein called "albumin" in the urine, it can lead to serious malnutrition, which can cause hair loss.
Even mild hypertension (high blood pressure) can lead to impaired kidney function, and should thus be aggressively controlled. It is wise have your blood pressure checked regularly, so that medication (such as an angiotensin inhibitor) can be started immediately if hypertension starts developing.
This article is a NetWellness exclusive.
Last Reviewed: Apr 01, 2004
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Philip W. Hall, 3rd, MD Professor of Medicine Emeritus Office of Medical Education School of Medicine Case Western Reserve University |
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