If you feel fine, having a low blood pressure is fine as well.

Q: You're always talking about high blood pressure. Mine is always on the low side, about 80/60. Is that a problem?

A: Healthy blood pressure is defined as anything under 120/80 millimeters of mercury (mm Hg). Yours certainly falls in that category. Whether it is too low depends on how you feel.

Low blood pressure is a serious problem when the pressure suddenly drops from normal to low, as happens with dehydration, blood loss, or shock.

Chronically low blood pressure is worrisome when it is accompanied by symptoms such as dizziness or fainting.

This can be a sign of an underactive or overactive thyroid gland, poorly functioning adrenal glands, anemia, mild dehydration, a low heart rate, and other conditions. It can also be caused by medications, especially those used to lower blood pressure.

In some people, blood pressure drops rapidly whenever they get out of bed or stand up from a chair (called postural hypotension); others experience a drop in blood pressure after eating (called postprandial hypotension).

These sudden drops can cause dizziness, lightheadedness, and even fainting.

Everyone feels a bit woozy now and then when standing up after sitting or lying down. If this happens to you often, or you sometimes get dizzy or feel lightheaded for no reason, I would check to make sure you are drinking enough water and don't have a condition that can cause low blood pressure.

I would also check to make sure that any medications you are taking aren't lowering your blood pressure too much.

But if you feel fine and don't have symptoms like those, I wouldn't worry about your blood pressure. In fact, it may be doing you some good, since the lower the pressure, the less strain on the heart. -- Richard Lee, M.D. Associate Editor, Harvard Heart Letter