Atherosclerosis is a potentially serious and progressive (gets worse over time) condition where the body’s medium and large arteries become clogged up by fatty substances, such as cholesterol. These substances are called plaques or atheromas.
The arteries
The circulation system is made up of arteries and veins. The blood is pumped from the heart and through the aorta (the main artery leading from the heart) before travelling through smaller and smaller arteries that branch off from each other.
The blood passes into tiny blood vessels, known as capillaries, where the oxygen in the blood is transferred into the cells of your body's tissues and organs. The blood returns to the heart through the veins.
Hardening and narrowing of the arteries is potentially dangerous for two reasons:
- Restricted blood flow to an organ can damage it and stop it functioning properly.
- If a plaque ruptures (bursts) it will cause a blood clot to develop at the site of the rupture. The blood clot can block the blood supply to an important organ, such as the heart, triggering a heart attack, or the brain, triggering a stroke.
Cardiovascular disease (CVD)
Atherosclerosis is a major risk factor for many different conditions involving the flow of blood. Collectively, these conditions are known as cardiovascular disease (CVD). Examples of CVD include:
- peripheral arterial disease: where the blood supply to your legs is blocked, causing muscle pain
-
coronary heart disease: where the main arteries that supply your heart (the coronary arteries) become clogged up with plaques
-
stroke: a very serious condition where the blood supply to your brain is interrupted
-
heart attack: a very serious condition where the blood supply to your heart is blocked
How common is atherosclerosis?
It is hard to estimate exactly how common atherosclerosis is. This is because it does not cause any noticeable symptoms until it reaches an advanced stage and triggers the onset of a related health condition, such as heart disease. However, it is thought that almost all adults have some degree of atherosclerosis.
A person’s arteries naturally get harder as they get older. Therefore, atherosclerosis tends to be more common in people who are over 40 years of age.
Atherosclerosis is more common in men than in women. It is thought that this is because the sex hormones that are used in the female reproductive cycle, such as oestrogen, provide protection against the effects of atherosclerosis.
Risk factors that can dangerously accelerate the process of atherosclerosis include:
- smoking
- a high-fat diet
- a lack of exercise
- being overweight or obese
- having either type 1 or type 2 diabetes
- having high blood pressure (hypertension)
Outlook
Left untreated, the outlook for atherosclerosis is poor. Treatment for atherosclerosis aims to prevent the condition from worsening to the point at which it can trigger a serious CVD, such as a heart attack. This can be achieved by using a combination of lifestyle changes, such as eating a healthier diet, and certain medications.