Topic Overview

If you check your blood pressure, you may wonder when an abnormal reading means you should call your doctor. This information can help you understand what your blood pressure numbers mean and when you need to call for help.

What do blood pressure numbers mean?

Your blood pressure consists of two numbers: systolic and diastolic. Someone with a systolic pressure of 117 and a diastolic pressure of 78 has a blood pressure of 117/78, or “117 over 78.”

It’s normal for blood pressure to go up and down throughout the day. But if it stays up, you have high blood pressure. Another name for high blood pressure is hypertension.

High blood pressure increases the risk of stroke, heart attack, and other problems. You and your doctor will talk about your risks of these problems based on your blood pressure.

Your doctor will give you a goal for your blood pressure. Your goal will be based on your health and your age.

In general, the lower your blood pressure, the better. For example, a blood pressure reading of less than 90/60 is healthy as long as you feel okay.

What can cause a short-term change in blood pressure?

Things like exercise, stress, and sleeping can affect your blood pressure. Some medicines can cause a spike in blood pressure, including certain asthma medicines and cold remedies.

A low blood pressure reading can be caused by many things, including some medicines, a severe allergic reaction, or an infection. Another cause is dehydration, which is when your body loses too much fluid.

When should you get help for an abnormal blood pressure reading?

One high or low blood pressure reading by itself may not mean you need to call for help. If you take your blood pressure and it is out of the normal range, wait a few minutes and take it again. If it’s still high or low, use the following guidance.

Call 911 anytime you think you may need emergency care. For example, call if:

• You passed out (lost consciousness).

Call your doctor now or seek immediate medical care if:

• Your blood pressure is much higher than normal (such as 180/120 or higher).
• You think high blood pressure is causing symptoms such as:
  • Severe headache.
  • Blurry vision.

Watch closely for changes in your health, and be sure to contact your doctor if:

• Your blood pressure measures higher than your doctor recommends at least 2 times. That means the top number is higher or the bottom number is higher, or both.
• You think you may be having side effects from your blood pressure medicine.