What is a Heart Attack? What are the symptoms? What are the main risk factors? How can we reduce the risk?

What exactly is a heart attack?

A heart attack is life threatening. It happens when the main blood vessels which carry oxygen to the heart muscle are closed or obstructed. This damages the heart, depriving it of the oxygen-rich blood it needs for normal functioning. 

The obstruction doesn’t happen by accident. It’s usually a result of atherosclerosis - a disease in which plaque builds up inside our arteries. This plaque is made up of fat, cholesterol and other substances from the blood. The exact cause of atherosclerosis isn't known, but it is known that an unhealthy lifestyle (including smoking, an imbalanced diet and physical inactivity) contributes to its development. 

Along with angina and heart failure, heart attack is one of the main symptoms of coronary heart disease - the leading cause of death in the UK. 

How common is a heart attack? 

Each year, around 200,000 people are hospitalised in the UK due to heart attacks. Fortunately many recover. An estimated 915,000 people alive in the UK today (640,000 men and 275,000 women) have survived a heart attack. However, recovering from a heart attack can take several months, require help with rehabilitation and have side effects ranging from depression to erectile dysfunction. So it makes sense to reduce the risk of having a heart attack, wherever possible. 

What are the main risk factors?

The main risk factors are:

  • High blood pressure is a major risk factor for both heart attack and stroke. This is important because high blood pressure usually isn’t accompanied by any symptoms. It is often accidentally discovered in a visit to your doctor. Fortunately blood pressure monitors are available for home testing. Good blood pressure control can significantly reduce the risk of both heart attack and stroke. 
  • Diabetes: Diabetes may increase your risk of heart attack by as much as 48%. There’s a further problem with diabetes. Patients may develop heart attack without any typical chest pain. It is called silent myocardial infarction and patients usually present with sweating, shortness of breath, light headedness, dizziness or fainting without any chest pain. These silent heart attacks account for almost 50% of heart attacks. 
  • Being overweight or obese: The World Heart Federation advises, ‘If you are overweight you may develop hypertension, diabetes and atherosclerosis.  These conditions will put you at high risk of cardiovasculardisease.’ 
  • Age and gender: Generally speaking, older age and male gender  are two minor risk factors for heart attack which we can’t change (the male risk is higher for under 65s but after that age there’s a similar risk for both men and women).
  • Family history: The risk of heart attack is higher if your father or brother was diagnosed with heart disease before the age of 55, or your mother or sister developed this before the age of 65
  • Lack of physical activity: This is a risk factor for heart attack and for a range of other serious illnesses. So taking more exercise has multiple health benefits. Aerobic exercise, such as walking, jogging, swimming or cycling can improve circulation, lower blood pressure and reduce the risk of type 2 diabetes. While a recent study showed that routine activities, such as car maintenance or gardening, can lower the risk of heart attack by 30%.

While the genes you inherit matter, research suggests that your lifestyle is a bigger risk factor. A healthy lifestyle can reduce the risk even if there is a family history – while an unhealthy lifestyle compounds the risk.

Traditionally saturated fat was seen as a risk factor but recent reviews of the research have suggested there isn’t convincing evidence for this, so this is now a more controversial issue. However, high cholesterol is a well-known risk factor for both heart attack and stroke. Having a healthy diet is an important prevention strategy for heart attack.

What are the warning signs of heart attack?

  • Chest pain: Most heart attacks present with a pressure or squeezing type pain or discomfort in the centre of the chest. This pain can radiate to your arms (left greater than right), belly or jaws.
  • Shortness of breath: A sudden onset shortness of breath should be taken seriously as it may be the only symptom of a heart attack
  • Sweating, nausea or light headedness: These symptoms can occur with or without (especially in diabetics) any pain. Be aware that just a cold sweating and nausea could be the only symptom of a heart attack particularly in patients with diabetes.

As each of these could be a warning sign of heart attack, the NHS advises you should dial 999 if you suspect you or someone you know is having a heart attack

How can we reduce the risk?

  • Don’t smoke. As explained earlier this is the biggest preventable risk factor.
  • Eat food rich in flavonoids (like bran, apples, pears, red wine, grapefruit, strawberries and some dark chocolate). This seems to reduce the risk if you’re a woman after the menopause - and eating at least 5 portions of fruit and vegetables a day seems to reduce the risk more generally. 
  • Stay physically active. The British Heart Foundation advises this can help reduce your risk of heart disease. 
  • If you're over 40 and living in the UK take up the offer of an NHS Health Check (which should be offered once every five years until you’re 74) to assess your risk of having a heart attack in the next 10 years.

Don’t take vitamin or antioxidant supplements just for the purpose of prevention of heart attack, as the BMJ advises there is no evidence they can help prevent heart disease.

Aspirin can help reduce the risk but unfortunately has potential side effects, such as bleeding and gastro intestinal problems. However if you’ve had a heart attack the benefits may outweigh the risks (with chewing the aspirin more effective than swallowing) so discuss this with your doctor. 


  • Heart attack is one of the main symptoms of coronary heart disease – the leading cause of death in the UK.
  • The main risk factors are smoking, high blood pressure, diabetes, being overweight or obese, high cholesterol, lack of physical activity, family history and age.
  • To reduce the risk follow a healthy lifestyle. In particular don’t smoke; eat fruit, vegetables and flavonoid rich food; stay physically active; and (if you’re over 40) take advantage of NHS Health Checks.
  • The main symptoms of a heart attack are chest pain, shortness of breath, cold sweating and nausea or light headedness.
  • If you or someone you know has symptoms of a heart attack call 999. 

Reviewed and updated by Sara Radenovic, February 2019. Next review date January 2023.