DEAR DR. DONOHUE: I will turn 65 next month and am in very good health. I am 5 feet 10 inches, have weighed 145 pounds for years and have a trim build with no gut. I look pretty good.

What I don’t understand is why I have absolutely no muscle tone whatsoever. My flesh is just like a wobbly bunch of marshmallows. It is nothing but a big bunch of flab. To make matters worse, my skin is starting to look like crepe paper on my legs. What’s it going to be like if I manage to live 10 or 15 more years?

Thank you for any advice. — G.K.

ANSWER: You can’t expect to have the same muscle tone and size that you had as a younger man. In youth, we are in an anabolic state — we’re growing and maintaining our growth. At older ages, we’re in a catabolic state — we’re shrinking, at least in muscle tissue, not in fatty tissue. Partly, this is due to the diminished production of testosterone that comes with aging.

Muscle tissue shrivels. That’s called sarcopenia. It happens to everyone. You can slow the process and perhaps reverse it by undertaking resistance exercise.

Resistance exercise is weightlifting. If your exercise program is mostly an aerobics program (running, jogging, swimming, biking), you need to incorporate some weightlifting into it. Get your doctor’s OK for such a program. Use a weight that you can lift eight times consecutively, and perform three sets of eight lifts. As you progress, increase the repetitions until you’re lifting the weight 12 times. At that point, add more weight — 2.5 to 5 pounds — and drop the repetitions back to eight.

Vary the kinds of weightlifting exercises you do. You’ll have to buy a book or borrow one from your local library to devise a program where you’re not doing the same exercises month after month. Every three or four months, change your routine.

DEAR DR. DONOHUE: I am 63. What would cause hemorrhaging conjunctiva? The lower half of my left eye fills with blood for weeks at a time. My blood pressure is OK. Blood tests show nothing abnormal.

My eye doctor sent me to my family doctor, and he sent me back to the eye doctor. The blood clears in about three weeks. Then I wake up, and it has happened again. What should I do?

ANSWER: The conjunctiva is a clear membrane that covers the front of the eye. Most people aren’t aware that they have one. You describe a subconjunctival (“sub” meaning “under”) hemorrhage. “Hemorrhage” is a far too melodramatic word to use in this condition. A few tiny, invisible blood vessels beneath the conjunctiva have broken. The eye looks frightful but isn’t painful. Vision isn’t affected. Trauma, coughing, sneezing or straining can be causes. Often, the vessels spontaneously break for no reason. Applying a warm compress to the closed eye, three times a day, can hasten the blood’s disappearance.

I don’t know how many times this has happened. If it’s more than twice, you need to be investigated for clotting disorders.

DEAR DR. DONOHUE: Please clarify the following. A person mails you a question. That person signs his or her name to the letter. You decide which questions should be published and send the questions and answers to various newspapers around the country.

When you send these questions and answers to newspapers, do you also send the writer’s name or initials and their addresses? Some medical subjects are embarrassing. Please explain how this works. — A.R.

ANSWER: I don’t send the writers’ letters. I have to condense the letters, and I use only initials to identify the writer. If a person doesn’t want his or her initials used, then I sign the letter “Anon.” I never include an address. Letters never leave my hands. I dispose of them.

I don’t communicate with the newspapers. The final product is distributed by King Features of New York.

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.