Exercise can lower blood pressure by 10 points, which can prevent the onset of high blood pressure or reduce blood-pressure medicine, says a U.S. expert.

A special four-page section in the September issue of the Harvard Heart Letter provides information on blood-pressure basics.

The newsletter advises to keep checking blood pressure — the doctor should check it at every visit, but measuring at home between visits is even better.

A diet for better blood pressure emphasizes fruits, vegetables, low-fat dairy products, whole grains, poultry, fish and nuts.

For those overweight, losing weight can lower blood pressure.

Smoking a cigarette can cause a 20-point spike in systolic blood pressure, and having more than one alcoholic drink a day can contribute to higher blood pressure, says the newsletter.

Too much sodium and too little potassium can boost blood pressure. Aim for less than 1.5 grams of sodium a day and at least 4.7 grams of potassium from fruits and vegetables such as bananas, oranges and potatoes.

Chronic lack of sleep can also contribute to high blood pressure.