DEAR DR. DONOHUE: What’s considered normal blood pressure? Mine is 132/88, and the doctor says that is not normal. It doesn’t sound high to me. I asked why he doesn’t prescribe medicine for me if this is not normal, but he didn’t answer. Is he being reasonable? – L.L.

ANSWER: The latest blood pressure guidelines are more stringent than the former ones. Now a normal pressure is one less than 120 over 80. The first blood pressure number is the systolic pressure, the force imparted to blood as it is ejected from the heart into the circulation. The second number, diastolic pressure, is the pressure in the circulation between heartbeats. Both numbers are important. If only one of them is higher than normal, that still constitutes high blood pressure.

Systolic pressures of 140 to 159 and diastolic pressures of 90 to 99 are designated as stage 1 hypertension (high blood pressure). Elevation of the systolic, the diastolic or both puts a person in the hypertensive range. Stage 2 hypertension is a systolic elevation of 160 or greater and a diastolic of 100 or higher.

That leaves a big gap in blood pressure readings. Systolic readings of 120 to 139 or diastolic readings of 80 to 89 constitute a new class called “prehypertension.” You are in that class.

People with prehypertension don’t need medicines. They do, however, need to make what are called lifestyle modifications. Weight loss, when indicated, is one of those modifications and a very important one. Limiting the use of salt is another. Exercising for 30 minute a day, every day if possible, brings down pressure. Limiting alcoholic drinks to two a day for men and one a day for women is part of lifestyle modification. Making sure your diet contains foods with a hefty amount of potassium, magnesium and calcium can also lower blood pressure. Potassium-rich foods include baked potatoes with skin, raisins, bananas, sweet potatoes, acorn squash, spinach, cantaloupe, oranges and orange juice, tomatoes and kidney beans. A good magnesium supply is found in green, leafy vegetables, unpolished grains, nuts and meats. Dairy products are the best source of calcium.

DEAR DR. DONOHUE: I have a positive AIDS test. Naturally I am distressed. My doctor took many other tests and says that at the present I don’t need any treatment. I would like to know your opinion on that, and I would also like to know what those tests are. Thank you. – G.K.

ANSWER: One of the tests your doctor had done is called the T-4 lymphocyte (also called CD4 T-helper cells) count. T-4 lymphocytes are responsible for protecting the body against a variety of infections, including the HIV virus, the cause of AIDS. The HIV virus targets these cells and destroys them, leaving a person vulnerable to unopposed HIV proliferation and infection from a number of other viruses, bacteria and fungi. If the T-4 count is above 350, many AIDS experts defer treatment.

The other test is a quantification of the viral particles in the blood. If the quantity is not high, then treatment can be postponed.

Your distress is understandable. However, today’s treatments of AIDS provide more than a glimmer of hope. Infected people are living longer and longer and are engaged in active, productive lives.

DEAR DR. DONOHUE: What are crabs, and how do you get them? How do you know if you have them? – S.W.

ANSWER: “Crabs” is the everyday name for pubic lice. They are most often transmitted through sexual relations. You know you have them if the pubic area becomes intensely itchy and you see specks of black discoloration on your undergarments. The actual louse is quite small, about one-tenth of an inch (.2 cm), so you have to strain to see one. You can also see and feel lice nits, the hard shells covering louse eggs and attached to pubic hair.

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.