Cardiac catheterisation and coronary angiography are generally considered to be safe procedures. However, as with all medical procedures, there are some risks.

The main risks of coronary angiography include:

• bleeding under the skin at the wound site (haematoma) – this should improve after a few days, but contact your GP if you're concerned
• bruising – it's common to have a bruise in your groin or arm for a few weeks
• allergy to the contrast dye used, causing symptoms such as a rash and a headache – this is uncommon, but you should discuss any allergies with your cardiologist (heart specialist) before having the procedure

In very rare cases, more serious complications of coronary angiography can occur. These include:

• damage to the artery in the arm or groin in which the catheter was inserted, with the blood supply to the limb possibly being affected
• heart attack – a serious medical emergency where the heart's blood supply is suddenly blocked
• stroke – a serious medical condition that occurs when the blood supply to the brain is interrupted
• damage to the kidneys caused by the contrast dye
• tissue damage caused by X-ray radiation if the procedure is prolonged
• death

The risk of a serious complication occurring is estimated to be less than 1 in 1,000. People with serious underlying heart problems are most at risk.

Your cardiologist should discuss the risks with you before the procedure.