Last Updated: December 23. 2010 1:00AM Dr. Paul Donohue: your Health

Dear Dr. Donohue: my husband is 66 years old and has been diagnosed with hyponatremia. He has high blood pressure and takes medicine for it. He is also an alcoholic, eats very little and has lost a lot of weight.

Will you please discuss hyponatremia? I’m at my wits’ end because he looks so bad. He sees a kidney specialist, and I found “hyponatremia” on a piece of paper he brought home from the doctor.

J.B.

Dear J.B.: Hyponatremia (HI-poe-nuh-TREE-me-uh) is a low blood level of sodium. It’s not really an illness. It’s a sign of many possible disorders. something in the body has gone wrong and makes the body retain too much water or lose too much sodium (salt). Excessive sweating, drinking way too much water, burns, vomiting, diarrhea, adrenal gland abnormalities, pituitary gland problems, liver and kidney diseases, and congestive heart failure are some of the things that lead to a blood sodium drop.

A frequent cause, and perhaps your husband’s cause, is diuretics — water pills. They’re often used for control of high blood pressure. many of them induce a loss of sodium. This is corrected by adjusting the diuretic dose.

Most of the time the sodium drop isn’t that great, and no symptoms are generated. I have to believe that applies to your husband. his doctor would not have let him come home if his sodium level was too low.

dear Dr. Donohue: I have a Baker’s cyst behind my left knee. I have been told it can be cured when I have my knee replaced. However, that is impossible because of another physical condition. I can get very little information about this disorder. I was told to wear an elastic stocking, which I do and which seems to help. what is a Baker’s cyst? are there things I should be doing?

W.K.

dear W.K.: ever hear of bursas? They’re small, pancake-shaped affairs that are wedged between bones and tendons to prevent friction when the tendon rubs against bone. a Baker’s cyst is a swelling of a bursa behind the knee. It’s actually connected to the knee joint by a tunnel. The tunnel has a one-way valve that closes as fluid from the knee finds its way to the bursa. The bursa swells. The basic problem, most often, lies with the knee itself — arthritis, torn cartilage or other joint problems. Baker’s cysts are quite common.

What’s this about needing a knee replacement to fix it? That’s not true. a doctor can drain the cyst with a needle and syringe. often, the cyst reforms. Injecting cortisone into the cyst after drainage lessens the chance of recurrence. Elevation of the leg and a compression bandage are helpful. So are anti-inflammatory medicines if you can tolerate them. In stubborn cases, a doctor can surgically remove such a cyst.

Write to Dr. at P.O. Box 536475, Orlando, FL 32853-6475. Readers may

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