What is Blood pressure?

Blood is carried from the heart to all parts of your body in vessels called arteries. Blood pressure is the force of the blood pushing against the walls of the arteries. Each time the heart beats (about 60-70 times a minute at rest), it pumps out blood into the arteries. Your blood pressure is at its highest when the heart beats, pumping the blood. This is called systolic pressure. When the heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure. 

Blood pressure is always given as these two numbers, the systolic and diastolic pressures. Both are important. Usually they are written one above or before the other, such as 120/80 mmHg. The top number is the systolic and the bottom the diastolic. When the two measurements are written down, the systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80). If your blood pressure is 120/80, you say that it is "120 over 80." Blood pressure changes during the day. It is lowest as you sleep and rises when you get up. It also can rise when you are excited, nervous, or active. 

Still, for most of your waking hours, your blood pressure stays pretty much the same when you are sitting or standing still. That level should be lower than 120/80. When the level stays high, 140/90 or higher, you have high blood pressure. With high blood pressure, the heart works harder, your arteries take a beating, and your chances of a stroke, heart attack, and kidney problems are greater.A blood pressure of 140/90 or higher is considered high blood pressure. Both numbers are important. If one or both numbers are usually high, you have high blood pressure. If you are being treated for high blood pressure, you still have high blood pressure even if you have repeated readings in the normal range.

 Symptoms      

For the most part, you can't tell if you have high blood pressure, and most hypertensive people have no symptoms. So the only way to find out if it's high is to have it measured. This statement may come as a surprise, because many people are convinced that they can tell when their pressure is high. It's certainly true that when you get angry or anxious you may feel yourself tensing up, and your heart pounding. You may even go red in the face, something that's often erroneously associated with high blood pressure. And you're right: your pressure is likely to be high at such times. But that's perfectly normal, and unless you spend your life being permanently angry, which fortunately most of us don't, it doesn't mean much. High blood pressure is of concern only when it's still high when you are not angry or tense.    

What do the numbers mean?

Every blood pressure reading consists of two numbers or levels. They are shown as one number on top of the other.

The first (or top) number is your systolic blood pressure. It is the highest level your blood pressure reaches when your heart beats.

The second (or bottom) number is your diastolic blood pressure. It is the lowest level your blood pressure reaches as your heart relaxes between beats.