Understanding Hypertension and Normal Blood Pressure

For years, physicians have referred to hypertension as the silent killer because it can exist with no obvious symptoms. Although some patients complain of dizziness, headaches or blurred vision, most patients only discover they need hypertension treatment when their blood pressure is taken.

Hypertension is a health condition in which blood pressure is persistently elevated. Blood pressure is a measure of the pressure of the blood against the blood vessel walls. Persistent high blood pressure puts undue stress on the heart, blood vessels and other organs.

 

High blood pressure is a serious health risk for many people. Hypertension can cause hardening of the arteries, heart attacks, strokes, and kidney damage.

Normal blood pressure for a healthy adult is 120/80…and just what does that mean?

 

Blood pressure is the pressure your blood exerts against your blood vessel walls. The pressure is higher when your heart contracts, and lower when it relaxes. A blood pressure cuff measures both pressure readings. The first number (the systolic) is your blood pressure when the heart contracts, and the second number (the diastolic) is your reading when the heart relaxes. If one or both of the measurements are higher than normal, you may have high blood pressure.

 

No one's blood pressure is constant. Exercise, a cigarette, a sudden burst of anger: All of these can raise our normal blood pressure readings, but they don't raise our blood pressure to dangerous levels for long periods of time. In the absence of high blood pressure symptoms, hypertension is diagnosed based on several blood pressure readings taken over a period of time.

After your doctor has taken your blood pressure, the reading may be compared to a blood pressure chart. The chart is very easy to read. Different levels of blood pressure are listed on the chart, with the highest levels at the bottom of the chart. Where you rank on the blood pressure chart gives the doctor an idea of how severe your hypertension is. The categories range from Mild all the way to Extreme Hypertension.

Category	Systolic BP (mmHg)	Diastolic BP (mmHg)
Optimal	Less than 120	Less than 80
Normal	Less than 130	Less than 85
High normal	130-139	85-89
Stage 1 Hypertension (Mild)	140-159	90-99
Stage 2 Hypertension (Moderate)	160-179	100-109
Stage 3 Hypertension (Severe)	180 and above	110 and above
Stage 4 Hypertension (Very Severe)	210 and above	120 and above

Because children naturally have a normal blood pressure that's lower than an adult's, a child is at risk for hypertension at much lower blood pressures:

 

National Heart, Lung and Blood Institute. (nd). High blood pressure. NHLBI Guide to Lowering High Blood Pressure.

Simon, H. (ed). High blood pressure. Well-Connected, March 2002.