Chronic Subdural Haematoma:

This page is intended as a patient/relative information source only. It is not a substitute for professional medical advice.

What Is A Subdural Haematoma?

A subdural haematoma is the term used to describe a collection of blood that accumulates under one of the coverings of the brain called the dura. A subdural haematoma is extremely common and in Leeds we see around two hundred cases per year.

There are two main types of subdural haematomas; acute and chronic. Acute means that the bleeding has happened quickly and recently. Chronic means that the blood has been present for some time, often weeks or even months. The rest of this article is about chronic subdural haematomas. Information about acute subdural haematomas can be found here.

What Causes A Chronic Subdural Haematoma?

A chronic subdural haemorrhage is caused by an injury to the head that isn’t always a particularly significant one. Chronic subdural haematomas progress slowly over a few weeks or months. They usually occur because the blood vessels which connect the brain to the skull become more stretched and fragile as the brain shrinks slowly as we get older. We often see this type of bleed in older people, those who take blood thinning medications, certain medical conditions and those who consume alcohol in excess.

How Is A Chronic Subdural Haematoma Diagnosed?

Someone with a chronic subdural might seek medical advice several weeks after their head injury. The symptoms of a chronic subdural can be quite vague and difficult to notice. Someone with a chronic subdural sufferer might complain of worsening memory problems, clumsiness, or drowsiness. About a third of patients with a chronic subdural haemorrhage have a fluctuating or changing conscious level. Sometimes, sufferers find that they have a weakness or a loss of sensation over one side of their body. If doctors believe that someone might have a subdural haemorrhage then they will organise a head scan (usually a CT) to obtain images of the brain.

A CT scan showing a chronic subdural haematoma

How Is A Chronic Subdural Haematoma Treated?

If a chronic subdural haemorrhage is not causing any problems to the patient, then it may well be left alone to resolve spontaneously.

If it is causing problems, and the patient is well enough to have an operation, then they would be taken to the operating theatre for evacuation of the blood.

If an operation is conducted then it usually involves ‘burr holes’. The operation will entail being put to sleep before some of the hair is shaved and a cut made in the head. Usually, two small ‘burr hole’ are drilled in the skull bone. Salt water is then flushed through the holes until the clotted blood is evacuated. Usually a rubber drain is put into the space where the blood was to drain any more fluid that might collect; this is usually taken out after a day or two.

Rarely, a craniotomy might be required to get all of the blood out. This is a larger operation that involves making a trap door in the skull bone to evacuate the clot.

What Is The Outlook?

Subdural haematoma is a serious condition and the outcomes can range from very good to very grave.

Generally, the outlook for chronic subdural is better than that for acute subdural haematoma. However, people who have a chronic subdural haematoma often have other medical problems or are frail anyway and this can complicate their time in hospital.

It is not uncommon for someone who has a chronic subdural treated to then develop another one and so medical and nursing staff will observe patients closely after the operation for any signs of this.


Page Author: Dr Tom Kilner, March 2011

Website created and edited by Ian Anderson