Heart disease and stroke may be inherited, but often they are the result of lifestyle. Changing eating, exercise and smoking habits can play a significant part in prevention.
Four out of five people who die from coronary heart disease are aged 65 or older. The risk of stroke doubles with each decade after the age of 55.
Men are more at risk than women and have attacks earlier in life. But death rates from heart disease and stroke for women are twice as high as those for all forms of cancer.
The risk for women increases as they approach menopause and continues to rise a they get older, possibly because of the loss of the natural hormone oestrogen.
Family history (heredity)
Children of parents with heart disease are more likely to suffer from the disease. Some races, such as Afro-Caribbeans, are more prone to coronary heart disease and stroke than others.
Smokers are twice as likely to suffer heart attacks as non-smokers, and they are more likely to die as a result. Smoking is also linked to increased risk of stroke.
The nicotine and carbon monoxide in tobacco smoke damages the cardiovascular system. Passive smoking may also be a danger.
Women who smoke and take the oral contraceptive pill are at high risk of heart disease and stroke.
Drinking an average of more than one drink a day for women or more than two drinks a day for men increases the risk of heart disease and stroke because of the effect on blood pressure, weight and levels of triglycerides – a type of fat carried in the blood.
Binge drinking is particularly dangerous.
The use of certain drugs, particularly cocaine and those taken intravenously, has been linked to heart disease and stroke.
Cocaine can cause abnormal heartbeat, which can be fatal, while heroin and opiates can cause lung failure. Injecting drugs can cause an infection of the heart or blood vessels.
The higher the blood cholesterol level, the higher the risk of coronary heart disease, particularly if it is combined with any of the other risk factors. Diet is one cause of high cholesterol – others are age, sex and family history.
High levels of LDL (low-density lipoprotein), or “bad cholesterol”, are dangerous, while high levels of HDL (high-density lipoprotein), or “good cholesterol” lower the risk of heart disease and stroke.
High blood pressure increases the heart’s workload, causing it to enlarge and weaken over time. When combined with obesity, smoking, high cholesterol or diabetes, the risk increases several times.
High blood pressure can be a problem in women who are pregnant or are taking high-dose types of oral contraceptive pill.
Failure to exercise is a cause of coronary heart disease as physical activity helps control cholesterol levels, diabetes and, in some cases, can help lower blood pressure.
People who are overweight are more likely to develop heart disease and stroke, even if they have none of the other risk factors.
Excess weight causes extra strain on the heart, influences blood pressure, cholesterol and levels of other blood fats – including triglycerides – and increases the risk of developing diabetes.
The condition seriously increases the risk of developing cardiovascular disease, even if glucose levels are under control. More than 80% of diabetes sufferers die of some form of heart or blood vessel disease.
Previous medical history
People who have had a previous heart attack or stroke are more likely than others to suffer further events.
Some links have been made between stress and coronary artery disease. This could be because it encourages people to eat more, start smoking or smoke more than they would otherwise have done.
Educating people about the risk factors of heart disease and stroke and attempting to persuade them to adopt a healthier lifestyle can have an impact on the number of people dying from heart disease and stroke.
Encouraging people to stop smoking, drink less, eat better and exercise regularly are particularly important.
Doctors can help by asking about smoking habits and encouraging patients to use nicotine replacement treatment, such as nicotine patches.
People should also have regular blood pressure readings, height and weight monitoring, and tests for cholesterol levels.
Those with high levels should be encouraged to improve their diet and can be treated for poor cholesterol levels with drugs – usually, statins or niacins.
The American Heart Association recommends that blood pressure should be no more than 140 over 90 Hg.
The association recommends a series of diets, with no more than 30% of calories coming in the form of fats, and limiting calories in the form of saturated fats to between 7 and 10%.
People at risk should have less than 200mg dietary cholesterol per day.
Sodium intake, most commonly found in salt, should also be controlled.
Between three and four sessions of moderate intensity exercise, lasting around 30 minutes a time, are recommended as the minimum for physical activity each week.
Ideal body mass index (BMI) – calculated by dividing weight in kilograms by the square of height in metres – is between 21 and 25, and the preferable waist circumference is no more than 88cm (35 inches) for women, 102cm (40 inches) for men.
For people already suffering from cardiovascular disease, the use of aspirin or warfarin, both of which prevent blood clotting, is recommended.
Other drugs, including ACE (angiotensin-converting enzyme) inhibitors to manage blood pressure, beta-blockers to control angina, heart rhythm or blood pressure, and oestrogen replacement in post-menopausal women, may also be used to prevent repeat incidents.