DEAR DR. ROACH: I recently had a hip replacement. I am 84, with hearing loss. My family says my hearing is worse after the operation. My daughter talked with several seniors who experienced the same thing. They think it has to do with the anesthesia. Fact or fiction? — D.W.

ANSWER: Possibly fact. Hearing loss is a known and rare occurrence after surgery, and there are several ways in which it can happen. You mentioned anesthesia: Several anesthetic agents, especially nitrous oxide, can cause temporary hearing loss, but nitrous oxide is not used as often during surgery as it once was. Changes in the fluid pressure in the ear also can cause both temporary and permanent hearing loss. Finally, antibiotics given around the time of an operation can cause hearing loss.

DEAR DR. ROACH: I recently attended a free introductory visit at my local health spa. It’s an interesting process. There is a circuit with 12 machines and 12 mats for doing cardio. Each exercise is done for 30 seconds, then you move to the next station. The circuit is supposed to be done twice at each session, three times per week. Can this really work to help you lose weight and get fit? Need I say, again, 30 seconds? Really — your opinion please. — E.Y.M.

ANSWER: There are two questions, and the first is on fitness. There, the answer is a resounding yes. High-intensity interval training has been clearly proven to improve muscle and cardiovascular fitness. If you were to follow the program at the gym, working hard but not overdoing it, you certainly would find that your ability to do the exercises would improve, your stamina would increase, and you’d likely feel better and have more energy. A 24-minute workout (24 stations of 30 seconds each, done twice) is enough (and a LOT better than no workout at all).

Unfortunately, just doing the exercise will not make you lose much weight. Losing weight comes from better dietary habits, which can help you eat less food and still feel satisfied. The combination of increased exercise and a little less food, especially less low-quality (“junk”) food, may help you lose a few pounds.

Losing weight shouldn’t be the goal, in my opinion. Losing weight and keeping it off is tough to do, but by exercising regularly and eating well, you can dramatically improve overall health and well-being even without weight loss.

DEAR DR. ROACH: I have large bubbles in a froth of small bubbles in my urine. Is this normal? I’m 86. — J.P.

ANSWER: Urine normally makes some bubbles, but a large amount of bubbles in the urine could mean abnormal protein in the urine.

In adults, protein in the urine ranges from benign to quite serious, depending on the cause. Nephrotic syndrome — the name given when protein output is very high, blood protein (albumin) is low and there is swelling (edema) in the body — is strongly associated with medical conditions such as diabetes mellitus and lupus. There are several kidney diseases that can cause large amounts of protein loss.

Your regular doctor is the right place to start. A simple urine dipstick can show protein in the urine, but a 24-hour collection is the definitive way to measure protein output. A kidney specialist often is consulted when there is unexplained large protein output.

READERS: The osteoporosis pamphlet furnishes details on how to prevent this universal condition. Readers can obtain a copy by writing: Dr. Roach — No. 1104, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name address. Please allow four weeks for delivery.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Health newsletters may be ordered from www.rbmamall.com.