DEAR DR. DONOHUE: Every year when I get my blood checked, the lab report shows that my white blood cell count is below normal.

It has been 2,300, 2,500 and 2,400, respectively, in the past three years. The lab says that normal is 3,500 to 9,600.

This has been going on for at least 10 years. My doctor wants me to see a hematologist. I am a 61-year-old woman who never gets sick. I’d like your opinion. My insurance will not cover this investigation, but I will pay for it if it seems appropriate. — M.M.

A: You have had a low white blood cell count for 10 years. You haven’t been sick in all that time. Your count has had no impact on your health.

White blood cells are our chief defense against infections. You have had no serious infections.

Low white blood cell counts can signal trouble with the bone marrow where these cells are made. They can be a sign of cancer that has invaded the marrow. Some medicines lower the white blood cell count. There’s a list of other causes. You have no symptoms to suggest those other causes.

You have two choices: Ignore the count, or see the hematologist (blood specialist). What’s the worst that can happen if you choose either? If you ignore the count, there is a remote possibility that you might be ignoring a process that will have an impact on your health. If you see the hematologist and nothing is wrong, you are out a consultation fee. To play it safe, I’d choose the latter.

Are you sure your insurance won’t pay for the consultation? You do have a legitimate medical condition — leukopenia (low white blood cell count). On what grounds are you being denied coverage? I’d appeal that decision.

c. North America Syndicate

DEAR DR. DONOHUE: Six years ago, I had a heart attack that resulted in triple bypass surgery, and I had to have my mitral valve replaced. Last year, my cardiologist informed me that my new mitral valve and my original aortic valve were leaking a little. He told me not to worry about it. I do worry. If you have a leak in your pipe in your home, you have it fixed immediately. I would think that applies to the body too. What do you think? — M.G.

A: You can’t compare heart valves to leaky pipes. They’re quite different, and they behave quite differently. Many people at older ages have slightly leaky heart valves that don’t interfere with heart action in the least. If the leaks were compromising your heart’s pumping, the doctor would have jumped right in with a suggestion for immediate repair.

Furthermore, unlike a pipe, valve leaks can but don’t always get worse.

Your doctor will check your heart regularly, and if the leaks are increasing, he will tell you then. For now, don’t dwell on them.

The booklet on heart-valve problems discusses these common medical conditions in depth. Readers can obtain a copy by writing: Dr. Donohue — No. 105, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My husband has chronic blepharitis and frequently develops hard buildups in both eyes that cause great discomfort. The doctor must remove them two times a month. What can be done to prevent them? — S.R.

A: Blepharitis (BLEF-uh-RYE-tiss) is inflammation of the eyelid margins, which become red and crusty. The crust can build up into hard deposits. A twice-a-day program of lid cleansing might eliminate the crusts.

Have your husband apply warm compresses (a wet washcloth) to closed lids for five to 10 minutes and then massage the lids. After the massage, he cleanses the lid margins with a cotton-tipped applicator dipped in a solution of one part baby shampoo and one part water. The doctor might have to prescribe an antibiotic ointment.