Blood pressure is shown as two numbers, such as 120/80 (say "120 over 80"). The top number is the pressure when the heart pumps blood. It is called the systolic pressure. The bottom number is the pressure when the heart relaxes and fills with blood. It is called the diastolic pressure. An ideal blood pressure for an adult is less than 120/80. High blood pressure is 140/90 or higher. Prehypertension is between 120/80 and 140/90.
What makes blood pressure go up?
Experts don't know the exact cause of high blood pressure. But they agree that some things can make blood pressure go up. They include not getting enough exercise and being overweight. Eating foods that have too much sodium (salt) and drinking too much alcohol also can raise blood pressure.
What are the symptoms?
Blood pressure that is higher than normal does not cause symptoms. Most people feel fine. They find out they have higher-than-normal blood pressure during a routine exam or a doctor visit for another problem.
How is prehypertension diagnosed?
A simple test with a blood pressure cuff is all you need to find out your blood pressure. The doctor or nurse puts the cuff around your arm and pumps air into the cuff. The cuff squeezes your arm. The doctor or nurse takes your blood pressure while letting the air out of the cuff.
If this test shows that your blood pressure is higher than normal, your doctor may have you come in for a follow-up visit to be tested again. This will confirm that you have prehypertension.
Some people only have higher blood pressure when they're at the doctor's office. This is called white-coat hypertension. If your doctor thinks this is getting in the way of measuring your true blood pressure, you may need to take your blood pressure at home.