Angina is a syndrome (a collection of symptoms caused by an underlying health condition) that is caused when the supply of oxygen-rich blood to the heart becomes restricted.
The most common symptom of angina is chest pain that is usually triggered by physical activity.
Most cases of angina are caused by atherosclerosis, which is a condition where the arteries become hardened and narrower, restricting the supply of blood. Risk factors for atherosclerosis include:
- advanced age,
- smoking,
- obesity, and
- a high-fat diet.
Diseases that affect the normal flow of blood, such as atherosclerosis, are known as cardiovascular diseases (CVD).
Types of angina
There are two main types of angina:
- stable angina, and
- unstable angina.
Stable angina
In cases of stable angina, the symptoms usually develop gradually, over time, and follow a set pattern. For example, you may only experience symptoms when climbing stairs, or if you are under a great deal of stress.
Symptoms usually only last for a few minutes and can be improved by taking medication that is known as glyceryl trinitrate.
Stable angina is not life-threatening on its own, but it is a serious warning sign that you have an increased risk of experiencing more serious conditions, such as a heart attack or a stroke.
Therefore, as well as treating the symptoms of angina, to reduce your risk of developing serious health conditions, you will also receive further treatment and, in some cases, surgery.
Unstable angina
In cases of unstable angina, the symptoms develop rapidly, they can persist even at rest, and can last up to 30 minutes. The symptoms of unstable angina may also be resistant to treatment with glyceryl trinitrate.
You may experience symptoms of unstable angina after previously having symptoms of stable angina. The symptoms of unstable angina can also occur in people who do not have a previous history of stable angina.
Unstable angina should be regarded as a medical emergency because it is a sign that the function of your heart has suddenly and rapidly deteriorated, increasing your risk of having a heart attack or stroke.
Unstable angina can be treated with medication and surgery.
How common is angina?
Angina is a common syndrome, particularly among older people. For example, it is estimated that in England, between 10-15% of women who are 65 years of age, or over, have angina.
The figure is slightly higher in men, with an estimated 10-20% of men aged 65, or over, having angina. This difference may be due to the fact that more men smoke.
Outlook
The outlook for stable angina is moderately good. It is estimated that 1 in every 100 people with stable angina will experience a fatal heart attack, or stroke, in any given year. While an estimated 0.5-2.6% of people will experience a non-fatal heart attack in any given year.
It should be stressed that it is possible to significantly lower your risk of having a fatal heart attack, or stroke, by making some simple lifestyle changes.
For example, if you are a smoker and obese, and you successfully quit smoking and achieve a healthy weight, you will reduce your risk factor by 400%.
See the ‘prevention’ section for more advice and information about making lifestyle changes.
The outlook for people with unstable angina can vary considerably, depending on a number of possible risk factors including:
- age,
- whether you have a history of heart disease,
- whether you have high-blood pressure (hypertension), and.
- whether you have a chronic condition, such as diabetes.
Depending on these factors, the risk that a person will experience a heart attack in the first 14 days after the onset of symptoms can range from between 2% to 16%.
