High Systolic Blood Pressure
Systolic blood pressure (the top number in a blood pressure reading) refers to the pressure within the blood vessels while the heart is beating. If your systolic blood pressure is more than 140 mmHg, you have high systolic blood pressure. For most people, the specific cause for this is unknown, but risk factors include having diabetes, smoking, and being overweight.
What Is High Systolic Blood Pressure?
Blood pressure is a measure of the pressure (or force) inside a person's blood vessels. Naturally, high blood pressure (also known as hypertension) occurs when the pressure within blood vessels is too high.
There are two pressures measured to determine a blood pressure reading -- the pressure while the heart is beating (referred to as systolic blood pressure) and pressure while it is relaxed (called diastolic pressure). When a person has high systolic blood pressure without a corresponding level of diastolic blood pressure, the condition is known as isolated systolic hypertension.
How Is It Measured?
Blood pressure is the amount of force (pressure) that blood exerts on the walls of the blood vessels as it flows through them. As blood is pumped from your heart into your blood vessels, enough pressure is created to send it to all other parts of your body.
To measure your blood pressure, your doctor will most likely use a sphygmomanometer, a device with which you're most likely familiar. A fabric cuff is wrapped around your arm and then slightly inflated. The blood pressure appears on a gauge attached to the cuff. Your doctor then reads the numbers from the gauge while air is released from the cuff. Blood pressure can also be measured with a blood pressure machine.
The two numbers measuring your blood pressure are written like a fraction: one number on top and one on the bottom. The number on top refers to the systolic blood pressure. It measures the pressure inside your blood vessels at the moment your heart beats.
The number on the bottom represents your diastolic pressure. It measures the pressure in your blood vessels between heartbeats -- when your heart is resting.