By now we all know that having consistently high blood pressure (120/80 mmHG or above) can cause myriad health problems, including heart attack and stroke. But should you be concerned if your problem is blood pressure that's too low? For most healthy adults, the systolic blood pressure (top number) is between 90 and 120 mmHG and the normal diastolic blood pressure (bottom number) falls between 60 and 80 mmHG. Although there's no set guideline for determining when blood pressure is too low (hypotension), medical experts usually define low blood pressure as pressure that's so low it causes symptoms, such as dizziness. For example, some people may have a blood pressure reading of 90/50 mmHG and have no symptoms of low blood pressure and, therefore, they don't have low blood pressure. Whereas other individuals who normally have high blood pressure may develop symptoms of low blood pressure if their blood pressure levels drop to 100/60 mmGH.

When Is Low Blood Pressure Bad for Your Health?

Although people with low blood pressure have a reduced risk of developing stroke, kidney disease and heart disease-athletes, people who exercise regularly, healthy-weight people and nonsmokers all tend to have lower blood pressures-when blood pressure is not sufficient to deliver enough blood flow to vital organs, such as the brain, it may cause the organs to malfunction or even be permanently damaged. For example, insufficient blood flow to the brain can deprive brain cells of oxygen and nutrients, making a person feel lightheaded, dizzy or even faint.

Symptoms of Low Blood Pressure

Low blood pressure can occur after prolonged bed rest; during the first 24 weeks of pregnancy; if there's a decrease in blood volume; if you're taking certain medications, such as diuretics, heart medications like beta-blockers and drugs for Parkinson's disease; and if you have chronic heart problems.

If your blood pressure readings usually run low and you're not experiencing any problems, you probably don't have to worry. However, if you're experiencing any of the these signs and symptoms of low blood pressure, check with your doctor to determine if there is an underlying medical problem. Symptoms to look for include:

  • Dizziness or lightheadedness
  • Fainting
  • Dehydration and unusual thirst-Dehydration can occasionally cause blood pressure to drop.
  • Lack of concentration
  • Blurred vision
  • Nausea
  • Cold, clammy, pale skin
  • Rapid, shallow breathing
  • Fatigue
  • Depression