Dear Dr. Donohue: Mom is 72 and diabetic. She is very active, but her feet hurt most of the time. She says it’s a burning feeling. She has no outward signs on her. Is there anything she can do or take to keep her from being in pain? — S.A.

Dear S.A.: Your mom’s leg nerves are being affected by her diabetes. It’s called diabetic neuropathy, a common complication of diabetes.

The trick is to get her blood sugar balance restored. That can keep things from worsening. Rigid blood sugar control is the best way to prevent such complications, and medicine can help. Meanwhile, she might apply capsaicin cream over the painful area.

Unless your mother controls her blood sugar level, the neuropathy can only get worse. She also should protect her feet by not walking barefoot.

Dear Dr. Donohue: I just read your column on fibromyalgia. My mother was once diagnosed with that, but later was correctly diagnosed as having acute leukemia. Meanwhile, she suffered for two painful months. Are fibromyalgia and acute leukemia often mistaken for each other? Please warn your readers to have a fibromyalgia diagnosis confirmed. — K.O.

Dear K.O.: I wholeheartedly second your words of caution. Fibromyalgia has such nondescript symptoms that it is easy to misdiagnose it and fail to catch an entirely different ailment. So a confirmatory examination is always in order. An initial exam may not identify acute leukemia, which can produce the same kind of general ache-all-over symptoms. I’m glad your mother got the correct diagnosis after all.

Fibromyalgia — also called fibrositis — has no specific test beyond the pressure test, in which the doctor presses on specified body areas to elicit telltale pain responses.

Dear Dr. Donohue: I am on a water drinking kick — maybe 12 to 15 glasses a day. Is there a maximum amount a person should be drinking? — J.B.

Dear J.B.: We need about 2 1/2 quarts of liquid a day for health. That’s not 2 1/2 quarts of water, mind you. When arriving at your total, include the fluid in food and other beverages.

Given the body’s ability to get rid of excess fluid, I can’t say that you are doing yourself any harm. Nor are you doing any good.

The undesired effect of excess fluid intake is to make you urinate more frequently.

How about letting me know what brought on your water binge?

— Write to Paul Donohue, M.D., P.O. Box 5539, Riverton, N.J. 08077.