I recently went for major abdominal surgery. I am curious about how my wound is going to heal. When I first came out of the operating theatre, my surgical wound didn’t hurt. But now, one week later, it does. I am a little worried. How do wounds heal?

There are several stages to wound healing.

When doctors carry out surgery (as opposed to a “natural” wound that has been inflicted upon your body), they are creating an artificial, “tidier” wound that is neater and will heal a lot better.

Nevertheless, artificially created or otherwise, wounds will heal in pretty much the same way through four major stages.

What are these stages?

Stage 1 is called the haemostasis stage.

Haemostasis means “stopping blood from flowing”. In this case, it is stopping the blood from flowing out of your newly formed wound.

Blood vessels near to the wound immediately contract to stop blood from rushing out. How effectively it does this is subject, among other factors, to how big and deep your wound is and how much a blood vessel has been severed.

In surgery, the surgeon immediately cauterizes these blood vessels and bleeding spots to seal them off.

You won’t be so lucky when you acquire a natural wound, and it’s up to you to maintain pressure on the bleeding site before your body’s mechanisms come into play.

Your body’s blood clotting mechanism is then activated. Platelets rush to the site of the wound to form a plug. Your clotting factors get activated through a complex cascade of reactions.

Once a clot is formed to prevent further blood from spilling out, your blood vessels dilate again to allow blood to carry more factors, nutrients, blood cells and antibodies to reach the wound area.

What happens after that?

We enter the defensive/inflammatory stage.

Now all the antibodies and white blood cells carried to the wound area function by destroying bacteria and removing debris and dead tissue.

White blood cells that are called neutrophils are the ones responsible for killing these bacteria and “eating up” debris. They last for about three days, and then they leave.

Other cells called macrophages arrive and continue to “eat up” the debris. They also release chemicals and growth factors to attract other immune cells.

At this stage, the wound will feel swollen and red, “hot” as well as painful. Basically, there is inflammation happening, and it is all part of the healing process.

That is why you didn’t really experience the swelling and pain immediately after your surgery (though you would have been doused with painkillers). And you are feeling it now.

Wow. I didn’t realise that. I thought my wound was getting infected!

It’s important to differentiate that sometimes. It can be very difficult. If in doubt, consult your doctor immediately.

Your wound is more likely to be infected (as compared to experiencing the normal healing process) if:

• You feel tired. People recovering from surgery feel better day by day. If you are feeling better, then suddenly worse, it might because you contracted an infection.

• You have a fever of more than 101°F. It is normal to run a temperature of 100°F or less following surgery, but if it reaches above 101°F, you are likely to have an infection.

• If the fluid draining from your wound is green, foul smelling or cloudy as opposed to being clear. Fluid draining from a wound is quite common following surgery.

• If you have increased pain.

• If your surgical wound is increasingly red and warm or exhibits red streaks.

What are the other stages?

The next stage is the proliferative stage. Here, the body’s objective is to fill and cover the wound.

Deep red granulation tissue fills the wound bed with connective tissue. New blood vessels get formed. Then the wound margins contract and pull towards the centre of the wound.

Epithelial cells come out from the wound bed and margins and migrate everywhere until the wound is entirely covered.

This stage takes anywhere from four to 24 days.

What is the last stage?

This is the maturation stage.

The new tissue slowly gains strength and flexibility. The collagen fibres remodel, reorganise, and mature. However, it will never be as good as your previous tissue, as it retains only 80% of your tissue strength before the injury or cut. This maturation phase takes anything from 21 days to two years.

It’s important to understand that different stages of wound healing can happen at the same time.

Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, e-mail starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.