DEAR DR. DONOHUE: Since I had hernia surgery in 1991, I produce what I consider to be an excessive amount of urine – 4 liters (more than 4 quarts) a day. I do not drink excessive amounts of water. Most often, at night I make a trip to the bathroom at least every hour, but there are some nights when I do not have to get up at all. I have seen countless physicians, and all say that this problem was not caused by the hernia surgery. The doctors always check me for diabetes, but the tests are always negative. If I try not to drink, I become dehydrated but continue the frequent urination. I have read on my own about the hypothalamus, pituitary gland and vasopressin. The doctors say this can’t be my problem. Can you shed some light on this? – R.B.

ANSWER: The volume of urine depends on how much liquid is drunk and how well the kidneys function. When a person does not guzzle excessive amounts of fluid, urine volume in excess of 3 liters (3 quarts) in 24 hours constitutes polyuria, an abnormal production of urine.

Diabetes is one cause of polyuria. You don’t have that. Low blood calcium and low blood potassium also can produce polyuria. Some medicines can bring it on.

There’s another kind of diabetes, diabetes insipidus, which is not related to sugar diabetes in any way other than causing an excessive production of urine. As your reading indicated, this kind of diabetes has to do with the production of a hormone called vasopressin. The hormone is made in the hypothalamus, a part of the brain that lies above the pituitary gland. The pituitary gland then secretes the hormone into the blood. Vasopressin conserves body fluid by lowering the production of urine. If the manufacturing of vasopressin lags, large quantities of urine are passed. That’s diabetes insipidus.

I agree with all the doctors you have seen. I don’t believe your hernia surgery is related to your polyuria, unless the anesthetic somehow messed with vasopressin production. I do think it would be worthwhile for you to have your vasopressin level measured.

DEAR DR. DONOHUE: I was hospitalized last year for congestive heart failure. I asked my doctor how that differs from heart failure. He said they are the same. That being the case, why are there two names for it?

Can congestive heart failure be a one-time occurrence? Or, once a person has it, is it a permanent condition, like diabetes? Do I say, “I had it” or “I have it”? To add to the confusion, I had atrial fibrillation. Is atrial fibrillation always present with congestive heart failure? – R.N.

ANSWER: Congestive heart failure and heart failure are one and the same. You can use whichever version you like. Why do we call cars automobiles sometimes, and sometimes just autos? The condition is one where the heart pumps so weakly that not enough blood circulates. Blood backs up and “congests” various organs, like the lungs. That’s why breathing is difficult in heart failure; the lungs are congested.

Congestive heart failure is a condition that can be remedied, but often not completely cured. Medicines can get the heart pumping stronger again. Should a person not take the prescribed medicines or should an additional stress be put on the heart, then that person can develop heart failure again.

In some instances, when the cause of heart failure has been eliminated, then the condition is eliminated. Those instances are not as frequent as are the instances when heart failure has a predilection to return.

Atrial fibrillation is not present in all cases of heart failure. It can be a factor in the genesis of heart failure, however. The erratic rhythm of atrial fibrillation affects the heart’s pumping ability. Getting rid of that rhythm or slowing it down improves the heart’s pumping. If atrial fibrillation was the sole cause of your heart failure and if it has been eliminated, then you can put your heart failure in the past tense.

The booklet on heart failure discusses this common ailment in depth. Readers can order a copy by writing: Dr. Donohue – No. 103, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Canadian with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com