Causes of atherosclerosis 

As you get older, it's thought that your arteries naturally begin to harden and narrow.

However, a number of things can accelerate this process. These are described below.

High-fat diets and cholesterol

Cholesterol is a type of fat that is essential for the functioning of the body. It helps to produce hormones, make up cell membranes (the walls that protect individual cells) and protect nerve endings.

There are two main types of cholesterol:

  • low-density lipoprotein (LDL)
  • high-density lipoprotein (HDL)

If you eat foods high in saturated fat, this can lead to high levels of LDL (known as "bad cholesterol").

LDL carries cholesterol from your liver to the cells that need it. If there is too much cholesterol for the cells to use, it can build up in the artery walls.

This leads to fatty deposits which, over time, reduce or completely block your blood supply. The fatty deposits are also known as plaques or atheroma.

Foods high in saturated fat include:

  • biscuits
  • cakes
  • bacon
  • sausages
  • processed meat
  • butter
  • cream

A lack of regular exercise, being obese and drinking excessive amounts of alcohol can also increase the levels of LDL cholesterol in your body.

Read more detailed information about high cholesterol and saturated fat.


Smoking can damage the walls of your arteries. Blood cells known as platelets will then clump together at the site of the damage to try to repair it. This can cause your arteries to narrow.

Smoking also decreases the blood's ability to carry oxygen around your body, which increases the chances of a blood clot occurring.

Read more about the health risks associated with smoking.

High blood pressure

If you have high blood pressure (hypertension), it will damage your arteries in the same way as cigarette smoke.

Your arteries are designed to pump blood at a certain pressure. If that pressure is exceeded, the walls of the arteries will be damaged.

High blood pressure can be caused by:

  • being overweight
  • drinking excessive amounts of alcohol
  • stress
  • smoking
  • a lack of exercise

Read more about high blood pressure.


If you have poorly controlled type 1 or type 2 diabetes, the excess glucose in your blood can damage the walls of your arteries.

Read more about type 1 diabetes and type 2 diabetes.


Being overweight or obese does not directly increase your risk of developing atherosclerosis and cardiovascular disease (CVD), but it does lead to related risk factors that do raise your risk.

In particular, overweight or obese people:

  • have an increased risk of developing high blood pressure
  • tend to have higher levels of cholesterol as a result of eating a high-fat diet
  • have an increased risk of developing type 2 diabetes

Read more about obesity.


Drinking an excessive amount of alcohol can cause high blood pressure (hypertension) and raised blood cholesterol levels, increasing your risk of developing atherosclerosis and cardiovascular disease.

Read more about alcohol misuse.

Family history

If you have a first-degree relative (a parent, brother or sister) with atherosclerosis and cardiovascular disease, you are twice as likely to develop similar problems compared with the rest of the population.


Rates of high blood pressure and diabetes are higher among people of African and African-Caribbean descent.

This means people in this group also have an increased risk of developing atherosclerosis and cardiovascular disease.

People of south Asian descent (those from India, Bangladesh, Pakistan and Sri Lanka) are five times more likely to develop diabetes than the population at large.

Again, this increases the risk of people in this group developing atherosclerosis and cardiovascular disease.

Read more about health issues that affect black people and health issues that affect people of south Asian descent.

Air pollution

Recent research suggests that air pollution, in particular traffic pollution, can speed up the progression of atherosclerosis.

Healthy hearts

Heart disease is the most common cause of death in the UK. Find out what to do to keep your heart fit for purpose

Page last reviewed: 13/06/2014

Next review due: 13/06/2016