If a person has high blood pressure it means that the walls of the arteries are receiving too much pressure repeatedly - the pressure needs to be chronically elevated for a diagnosis of hypertension to be confirmed. In medicine chronic means for a sustained period; persistent.
High blood pressure statistics
In the USA approximately 72 million people have high blood pressure - about 1 in every 3 adults, according to the National Heart Lung and Blood Institute. The National Institutes of Health (NIH) estimates that about two-thirds of people over the age of 65 in the USA have high blood pressure.
In the UK, The National Health Service, estimates that about 40% of British adults have the condition.
In this article we will take you through what high blood pressure is, common causes, how it is diagnosed and the symptoms that often accompany it. We will also discuss the available treatments for high blood pressure and changes that you can make to help reduce your risk of suffering with high blood pressure.
Contents of this article:
Measuring blood pressure
The heart is a muscle that pumps blood around the body constantly - during every second of our lives. Blood that has low oxygen levels is pumped towards the lungs, where oxygen supplies are replenished. The oxygen rich blood is then pumped by the heart around the body to supply our muscles and cells. The pumping of blood creates pressure - blood pressure.
When we measure blood pressure, we gauge two types of pressure:
- Systolic pressure - the blood pressure when the heart contracts, specifically the moment of maximum force during the contraction. This happens when the left ventricle of the heart contracts.
- Diastolic pressure - the blood pressure between heartbeats, when the heart is resting and dilating (opening up, expanding).
When a person's blood pressure is taken the doctor or nurse needs to measure both the systolic and diastolic pressures. The figures usually appear with a larger number first (systolic pressure), followed by a smaller number (diastolic pressure). The figure will be followed by the abbreviation "mmHg", which means millimeters of mercury.
If you are told that your blood pressure is 120 over 80 (120/80 mmHg), it means a systolic pressure of 120mmHg and a diastolic pressure of 80mmHg.
What is high blood pressure?
Anyone whose blood pressure is 140/90mmhg or more for a sustained period is said to have high blood pressure, or hypertension.
Blood pressure is usually divided into five categories:
Hypotension (low blood pressure)
Systolic mmHg 90 or less, or
Diastolic mmHg 60 or less
Systolic mmHg 90-119, and
Diastolic mmHg 60-79
Systolic mmHg 120-139, and
Diastolic mmHg 80-89
Stage 1 Hypertension
Systolic mmHg 140-159, and
Diastolic mmHg 90-99
Stage 2 Hypertension
Systolic mmHg over 160, and
Diastolic mmHg over 100
Symptoms of high blood pressure
Most people with high blood pressure will not experience any symptoms until levels reach about 180/110 mmHg.
High blood pressure symptoms typically include:
- Headache - usually, this will last for several days.
- Nausea - a sensation of unease and discomfort in the stomach with an urge to vomit.
- Vomiting - less common than just nausea.
- Dizziness - Lightheadedness, unsteadiness, and vertigo.
- Blurred or double vision (diplopia).
- Epistaxis - nosebleeds.
- Palpitations - disagreeable sensations of irregular and/or forceful beating of the heart.
- Dyspnea - breathlessness, shortness of breath.
Anybody who experiences these symptoms should see their doctor immediately.
Children with high blood pressure may have the following signs and symptoms:
- Blurred vision.
- Bell's palsy - inability to control facial muscles on one side of the face.
Newborns and very young babies with high blood pressure may experience the following signs and symptoms:
- Failure to thrive.
- Respiratory distress.
People who are diagnosed with high blood pressure should have their blood pressure checked frequently. Even if yours is normal, you should have it checked at least once every five years, and more often if you have any contributory factors.
On the next page we look at the causes of high blood pressure and how it is diagnosed. On the final page we examine the available treatments for high blood pressure, how lifestyle changes can help reduce blood pressure and the complications of high blood pressure.