Video: What is blood pressure?

Your heart is a pump.

When it contracts, or beats, it sends a surge of blood through the vessels, increasing blood pressure. This is called systolic pressure. When your heart relaxes between beats, your blood pressure decreases. This is called diastolic pressure.

For example, if your systolic pressure is 120 and your diastolic is 70, your blood pressure is recorded as 120 over 70.

Monitoring your blood pressure at home is easy to do. It's done with a blood pressure monitor. There are two main types: manual, also called aneroid, and automatic.

Automatic equipment contains electronics that sense the pulse wave under an inflated arm cuff. Automatic equipment minimizes human error and is recommended if you have hearing or vision loss.

Using the proper cuff will help ensure an accurate reading. Look for a D-ring cuff style for easier use. Children and adults with smaller or larger than average-sized arms may need special-sized cuffs.