Q. Should I take a baby aspirin a day for my health? I don't have heart disease, diabetes, or anything else.

A. Not necessarily. Even low-dose aspirin may cause serious brain bleeds. This is rare, occurring in about 1 per 1,000 aspirin users per decade, but it can be fatal or cause a stroke. Aspirin also causes major bleeding from stomach ulcers in about 7 per 1,000 users per decade, sometimes requiring blood transfusions.

But if you are a man older than 40, a postmenopausal woman, or you're younger but have risks such as hypertension, diabetes, cholesterol or smoking, then aspirin may save your life, reducing heart-attack risk by 28 percent.

So who should take aspirin? According to the American Heart Association, anyone with a 10 percent or higher risk of heart disease in 10 years — as long as you don't have a condition that unduly increases your risk for brain or gastrointestinal bleeds, like previous bleeding ulcers.

Ask your doctor if you qualify. Some experts, such as the U.S. Preventive Services Task Force, use a 6 percent or even lower 10-year risk.

You can find your risk at www.intmed.mcw.edu /clincalc/heartrisk.html.

You'll need to input information like total and HDL (good) cholesterol, blood pressure and whether you smoke. Dr. Wiley Chan, director of guidelines and evidence-based medicine for Kaiser Permanente Northwest, says that if you're on blood-pressure pills and your pressure is now normal (less than 140/90), you should input 140/90 as your pressure.

If you smoke and have no other risk factors, your risk is above 10 percent if you're a man 45 or older, or woman 55 or older. Anyone with diabetes, previous heart attack or stroke, or heart or leg bypass surgery should ask their doctor about starting aspirin.

Some experts advise that aspirin be taken indefinitely. The elderly may realize greater benefits because they're at higher heart disease and stroke risk, but the risk for bleeding ulcers may be two to three times higher above age 70.

And yes, the dose is one baby aspirin (81 milligrams) every morning; higher doses don't work better and cause more bleeds. Enteric-coated aspirin has not been clearly shown to reduce bleeds.

On May 15, the American Journal of Cardiology reported a study of 192,036 patients that found taking even one adult aspirin (325 milligrams) a day caused more episodes of serious bleeding than a baby aspirin a day.

Dr. Landis Lum is a family-practice physician for Kaiser Permanente and an associate clinical professor at the University of Hawai'i's John A. Burns School of Medicine. Send your questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Hono-lulu, HI 96802; fax 535-8170; or write islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.