What is considered a good blood pressure?

A blood pressure reading below 120/80 mm Hg is a good blood pressure reading, according to the National Heart, Lung, and Blood Institute. Low readings are usually best, but the American Heart Association warns that low blood pressure can cause unpleasant side effects, such as dizziness or dehydration.

The National Heart, Lung, and Blood Institute states that eating a healthy, low-sodium diet and exercising regularly can help keep blood pressure at a healthy level. WebMD warns that a reading higher than 140/90 mm Hg can lead to serious problems, such as heart disease, and may require medication or lifestyle changes.