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HealthInfo Waitaha Canterbury

General surgical risks

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Your risk of complications after surgery depends on the type of procedure you're having and your general physical health. Before your surgery, your surgeon will talk through possible risks with you and answer your questions.


This can be an issue during surgery or afterwards. If you bleed too much, you may need to go back to the operating theatre for more surgery and you could need a blood transfusion. You may develop a haematoma (collection of blood) that needs draining.

Blood clots

Blood clots are a serious complication. They can cause deep vein thrombosis (DVT) or pulmonary embolus (PE). Any lengthy operation can cause blood clots, but your healthcare team make every effort to avoid them. You're usually given special stockings to wear during your stay in hospital. You may also be given special medication to minimise the risk, such as a daily injection into your tummy.


These could include chest, urine and wound infections that can be slow to heal. In some surgery there is also a risk of infection in the blood (septicaemia) that can make you very unwell. Antibiotics will be used to treat these infections if they develop.


Following surgery, you'll have some pain. Everyone experiences pain differently. The surgical and anaesthetic team will prescribe pain relief and advise you on how to manage your pain when you go home.

Tissue injury

During surgery there is some risk of injury to surrounding tissue or organs. The surgeon will try to minimise any chance of this occurring.

Occasionally, there may be damage to nerves in the area of the surgery. This can cause numbness on the skin near the wound that could last for weeks, months or even permanently if the nerve doesn't heal.

Injured or damaged nerves can cause pain. If you're still getting pain after two to three months, you should see your GP.

Delayed recovery

Some people take longer to recovery after surgery than others. This can depend on things such as age or pre-existing illness such as diabetes or immune problems.


Your surgeon will explain what type of scar you're likely to have after your surgery.

Most scars fade over time. Some people experience pain from their scar for some time after surgery, but this usually improves over time. Some people develop thickening of their scars. This is called hypertrophic scarring. Some people have a condition called keloid scarring, which is caused by an overgrowth of scar tissue.

You should tell your surgeon if you have had trouble with scarring before. Your surgeon may recommend supporting your wound with a type of tape for six to eight weeks after the surgery. This can help reduce scarring.

Written by HealthInfo clinical advisers. Last reviewed June 2022.

See also:

Having an anaesthetic

Page reference: 542846

Review key: HIGSR-542846