Surgery is recommended for most subdural haematomas. Very small subdural haematomas may be carefully monitored first to see if they heal without having an operation.

If surgery is recommended, it'll be carried out by a neurosurgeon (an expert in surgery of the brain and nervous system).

There are 2 widely used surgical techniques to treat subdural haematomas:

• craniotomy – a section of the skull is temporarily removed so the surgeon can access and remove the haematoma
• burr holes – a small hole is drilled into the skull and a tube is inserted through the hole to help drain the haematoma

A craniotomy is the main treatment for subdural haematomas that develop soon after a severe head injury (acute subdural haematomas).

During the procedure, the surgeon creates a temporary flap in the skull. The haematoma is gently removed using suction and irrigation, where it's washed away with fluid.

After the procedure, the section of skull is put back in place and secured using metal plates or screws.

This is usually performed under a general anaesthetic, which means you'll be asleep while it's carried out.

Burr hole surgery is the main treatment for subdural haematomas that develop a few days or weeks after a minor head injury (chronic subdural haematomas).

During the procedure, one or more small holes are drilled in the skull and a flexible rubber tube is inserted to drain the haematoma.

Sometimes the tube may be left in place for a few days afterwards to drain away any blood and reduce the chances of the haematoma coming back.

Burr hole surgery is often carried out under general anaesthetic, but is sometimes done under local anaesthetic.

This means you remain awake during the procedure, but the scalp is numbed so you do not feel any pain.

Like all operations, surgery for a subdural haematoma carries a risk of complications. Most of these complications are uncommon, but they can be serious.

Problems that can occur after subdural haematoma surgery include:

• further bleeding on the brain
• infection of the wound or skull flap
• a blood clot in a leg vein (deep vein thrombosis)
• fits (seizures)
• a stroke

There's also a chance that not all of the haematoma can be removed and that some of the symptoms you had before surgery continue. These may get better over time or they may be permanent.

In some cases, the haematoma can come back during the days or weeks after surgery. If this happens, further surgery may be needed to drain it again.

If surgery goes well and you do not have any complications, you may be well enough to leave hospital after a few days.

If you do develop complications, it may be several weeks before you're able to go home.

If you have persistent problems after surgery, such as memory problems or weakness in your limbs, you may need further treatment to help you gradually return to your normal activities.

The length of time it takes to recover from a subdural haematoma will vary from person to person.

Some people will feel a lot better after a few weeks, while others may never make a full recovery.

Read more about recovering from a subdural haematoma.