DEAR DR. ROACH: I am an 85-year-old male. I walk a mile every day, have a pacemaker and hearing aids, and use a CPAP machine. All in all, I feel pretty good, but there is something that bothers me and my doctor has no answer. Several times a day, or at night in bed, with no consistency, I get hot flashes and a cold sweat, starting at my head and then my face and back. There is no pain and no fever. It lasts from three to around seven minutes, then goes away. Could it a symptom of something else? Any suggestions? Thanks! — R.P.C.

ANSWER: Hot flashes in men can be a sign of low testosterone. They are common in men who are treated with medications to lower testosterone as part of prostate cancer therapy; they are uncommon in men who lose the ability to make testosterone as part of normal aging. However, it would be wise to check your testosterone level. This test should be done at about 8:00 in the morning, as that is normally the highest level in the day. High thyroid levels cause sweating, but not normally of the intermittent type you describe.

Hot flashes can also be caused by certain rare tumors. Carcinoid tumors and pheochromocytoma are tumors that affect blood pressure. People with symptomatic pheochromocytoma always have high blood pressure, usually very high at the time of the flushing. These tumors can also be looked for with 24-hour urine testing by the lab.

Some infections can cause intermittent hot flashes and sweats. Tuberculosis is the classic cause, but other serious causes, such as infections of the heart valve, may also cause intermittent sweating.

None of these scary-sounding conditions is likely, but since this seems to have been going on for a while, it might be time for your regular doctor to try to identify a possible cause. However, sometimes a cause is never found. In your case, the sleep apnea (presumably that’s why you use a CPAP machine) has often been associated with sweats at nighttime (but not so much during the day).

No cause may be identified, but I think it’s worth a look, for your peace of mind.

DEAR DR. ROACH: I am going to a very competent optometrist who has diagnosed glaucoma in both of my eyes six months ago. As there is good history and documentation of the condition of my optic nerve over several years, I do not have to use drops for now. I must continue to return every six months to have my eyes checked so that he may assess my condition. I am content with this direction from the optometrist, but with a condition such as glaucoma, would I better served by going to an ophthalmologist? — J.P.

ANSWER: Optometrists can treat glaucoma in all 50 states now. Optometrists are expert in diagnosing and treating most cases of glaucoma; however, they may still refer to an ophthalmologist in cases where the diagnosis is uncertain; when multiple medications are prescribed or the patient cannot tolerate them; or when the disease progresses despite treatment. In your case, it sounds like an ophthalmologist isn’t needed. I believe optometrists would refer their patients to an ophthalmologist if they felt it were necessary.

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 send mail to 628 Virginia Dr., Orlando, FL 32803.