DEAR DR. DONOHUE: When my nearly 30-year-old daughter had an X-ray a few years ago, the doctor told her she had the bones of an older woman. A few weeks ago, after an accident, she had X-rays and was told the same thing. She was advised to take calcium and exercise. (She does water aerobics.) What would cause the aging of her bones? No doctor has ever told her why this has happened. – J.L.

ANSWER: When the doctors say her bones look old, they’re saying that her bones are showing some osteoporosis, something that should not happen to a woman’s bones until menopause. Your daughter cannot ignore this. She should report it to her family doctor.

Osteoporosis at such an early age calls for an explanation. She might not be making sufficient estrogen and her bones are losing calcium – the same cause of menopausal osteoporosis. If that is the case, the doctor has to find out why. She can take estrogen in pills if this proves to be the reason why her bones look like they do.

Or she might not have stored as much calcium in her bones as she should have when she was younger. That can be partially corrected by taking calcium supplements and vitamin D, which promotes calcium absorption. A woman her age requires 1,000 mg of calcium a day and 200 IU of vitamin D.

Another possibility is an overactive parathyroid gland. Parathyroid hormone, when secreted in constantly excessive amounts, takes calcium from bone and leads to osteoporosis.

I can’t say for sure what her problem is. I can tell her she has to get to the bottom of this quickly.

And I can add a word about exercise. Weight-bearing exercise is the kind of exercise she must perform. “Weight-bearing” means her bones have to support her body weight during the exercise. Jogging and walking are weight-bearing exercises. The body supports the entire weight of the body during those activities. Water aerobics is excellent exercise for the heart and lungs but is not an excellent weight-bearing exercise – the water’s buoyancy supports body weight. She needs land-based exercise, including weightlifting.

DEAR DR. DONOHUE: My 17-year-old nephew has had two episodes of spontaneous pneumothorax this year. He otherwise is in good health. I have scoured all medical books but can’t find a satisfactory answer. I would appreciate any information on this subject. – S.S.

ANSWER: A double-layered membrane covers each lung. That’s the pleura. There’s a slight gap between the two layers, so one rubs over the other effortlessly when air comes into and out of the lungs. A pneumothorax (NEW-moe-THOR-axe) is air that has escaped into the gap between the two pleural layers. It most often comes from the rupture of a bleb, a small cyst. Such a bleb or blebs can be there from infancy, and most never cause trouble throughout life. Your nephew, however, is not so fortunate. Treatment depends on how much air gets into the pleural space. If it’s only a little, the body can absorb it on its own. If it’s more, the lung is compressed, breathing becomes difficult and there’s an urgency to remove it. That can be done with a large needle, a tube or surgery, depending on circumstances.

Recurrences are common.

DEAR DR. DONOHUE: I take ProAmatine for vasodepressive syndrome. On the information sheet for this medicine, it says it can depress your veins. I see fewer and fewer of my veins. Is this going to affect veins in my brain? – J.H.

ANSWER: Vasodepressive syndrome is a condition where blood pressure drops when a person rises from the sitting or lying position. It can make one feel dizzy or can make a person faint. ProAmatine (midodrine) keeps arteries and veins slightly more constricted so that blood pressure doesn’t drop when you change positions. It doesn’t shrink your veins. It won’t affect your brain or its blood vessels.

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.