You can find out if you have high blood pressure by having your blood pressure checked regularly. Most doctors will diagnose a person with high blood pressure on the basis of two or more readings, taken on several occasions. A consistent blood pressure reading of 140/90 mm Hg or higher is considered high blood pressure, another term for hypertension.

Some people experience high blood pressure only when they visit the doctor's office. This condition is called "white-coat hypertension." If your doctor suspects this, you may be asked to monitor your blood pressure at home or asked to wear a device called an ambulatory blood pressure monitor. This device is usually worn for 24 hours and can take blood pressure every 30 minutes.

Tips for Having Your Blood Pressure Taken

Don't drink coffee or smoke cigarettes 30 minutes before having your blood pressure measured.
Before the test, sit for five minutes with your back supported and your feet flat on the ground. Rest your arm on a table at the level of your heart.
Wear short sleeves so your arm is exposed.
Go to the bathroom prior to the reading. A full bladder can change your blood pressure reading.
Get two readings, taken at least two minutes apart, and average the results.
Ask the doctor or nurse to tell you the blood pressure reading in numbers.