Summary

In this Study Session, you have learned that:

• Hypertension is a major public health problem that affects many people in the world.
• Blood transports oxygen, nutrients and other substances such as hormones around the body to where they are needed, and it removes waste products, including carbon dioxide.
• Blood consists of a liquid called plasma, containing suspended red blood cells, which carry oxygen attached to haemoglobin; white blood cells, which fight infection; and platelets, which help in blood clotting.
• The heart and blood vessels (arteries, capillaries and veins) form the cardiovascular system.
• The heart pumps blood around the pulmonary circulation through the lungs and around the systemic circulation through the rest of the body. It has four chambers, which separate the oxygenated blood returning from the lungs and the deoxygenated blood returning from the rest of the body.
• Blood pressure measurements produce two numbers: the systolic pressure measured when the heart contracts and the diastolic pressure measured when the heart relaxes. The unit of measurement is in mmHg.
• The risk factors for hypertension include being overweight, old age, poor nutrition, smoking, lack of exercise and excessive alcohol intake.
• Community approaches to reducing the risk of hypertension include supporting people to lose weight, live a less stressful lifestyle and give up smoking, for example by using DASH - the dietary approach to stop hypertension. Reducing salt intake also helps to reduce hypertension.