Angina is chest pain that occurs when the blood supply to the muscles of the heart is restricted. It usually happens because the arteries supplying the heart become hardened and narrowed.

The pain and discomfort of angina feels like a dull, heavy or tight pain in the chest that can sometimes spread to the left arm, neck, jaw or back.

The two main types of angina are stable angina and unstable angina.

• Stable angina – where angina attacks are brought on by an obvious trigger (such as exercise) and improve with medication and rest
• Unstable angina – where angina attacks are more unpredictable, occurring with no obvious trigger and continuing despite resting

Stable angina isn’t life-threatening on its own. However, it’s a serious warning sign that you’re at increased risk of developing a life-threatening heart attack or stroke.

Some people develop unstable angina after previously having stable angina, while others experience unstable angina with no history of having angina before.

Unstable angina should be regarded as a medical emergency, because it’s a sign that the function of your heart has suddenly and rapidly deteriorated, increasing your risk of having a heart attack or stroke.

Contagious for about 7-10 days.