Subdural haematoma 


This CT scan shows a haematoma bulding up on the right side of the skull 

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A subdural haematoma is a serious brain condition that is often caused by a head injury. Blood collects between the skull and the surface of the brain.

Symptoms of a subdural haematoma can include:

  • vomiting
  • mental confusion
  • coma

Symptoms can appear quickly or may develop over time depending on the type of subdural haematoma (see below).

Read more about the symptoms of a subdural haematoma.

A subdural haematoma occurs when a blood vessel in the space between the skull and the brain (the subdural space) is ruptured. Blood escapes from the ruptured blood vessel, leading to the formation of a blood clot (haematoma), which places pressure on the brain and may cause brain damage.

Read more about the causes of a subdural haematoma.

Types of subdural haematoma

A subdural haematoma can be:

  • acute – the haematoma forms immediately after the initial injury
  • subacute - the haematoma forms up to a week after the initial injury
  • chronic – the haematoma forms over a period of two to three weeks after the initial injury

These are discussed in more detail below.

Acute subdural haematoma

Acute subdural haematomas are the most serious type of subdural haematoma. They usually occur after severe, high-impact head injuries, often caused by motor vehicle accidents, falls and physical assaults.

An acute subdural haematoma is a medical emergency that requires immediate admission to a hospital. Surgery is usually required to remove the haematoma.

Subacute subdural haematoma

Subacute subdural haematomas are less common, and often harder to detect, than other types of subdural haematoma.

The signs and symptoms can appear days, or even weeks, after an injury and will be similar to those of an acute subdural haematoma.

Chronic subdural haematoma

Chronic subdural haematomas are more commonly seen in older people. It is thought they occur because the natural ageing process makes the brain more vulnerable to injury in some people.

This means that even a minor injury can cause bleeding inside the subdural space (in around half of all cases, the injury is so minor that the person cannot remember it).

The symptoms of a chronic subdural haematoma often develop several weeks after the initial injury, because our brain usually shrinks as we get older, creating more subdural space for the haematoma to expand into before it causes any noticeable symptoms.

Chronic subdural haematomas may also be regarded as a medical emergency. Surgery is usually required.

Read more about how a subdural haematoma is treated.


Acute subdural haematoma carries a high risk of death. Age is an important factor that affects a person’s outlook. For example, people who are:

  • under 40 years old have a 20% risk of dying
  • 40 to 80 years old have a 65% risk of dying
  • 80 years old or over have an 88% risk of dying

People who survive an acute subdural haematoma usually take a long time to recover from the effects of the haematoma. The recovery time will depend on the severity of the haematoma. There can also sometimes be permanent physical and mental disabilities.

Read more about recovering from a subdural haematoma.

Less information is available about subacute subdural haematomas as they are less common. However, the outlook for a subacute subdural haematoma is often better than for an acute subdural haematoma.

The outlook for a chronic subdural haematoma is also much better than the outlook for acute subdural haematoma. However, the condition still carries a moderately high risk of death. An estimated 1 in 20 people will die within the first 30 days after having surgery to treat a chronic subdural haematoma.

Page last reviewed: 31/08/2013

Next review due: 31/08/2015


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The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Chronicles said on 12 June 2014

I too was on Warfarin and got overdosed stopping another drug. My SDH started with four day very severe headache, and vomiting, which was diagnosed as "Tension Headache".
On 4th day INR was checked and found to be over 8. Another call to GP led to me being hospitalised, blood taken and two scans revealed Right SDH. Needless to say the pain was unbearable. I was treated very well in hospital. Warfarin stopped, and will be starting another anti-coagulant when dosage has been decided by the doctors. Am recovering slowly.

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suz1981 said on 24 December 2012

My 68 year old mother recently suffered from a subdural haematoma. The first symtoms she had was diarrhea, vomiting and constant headache. The diarrhea and vomiting stopped but the headache continued. She became weak, dehydrated, disoriented. Dr diagnosed her with a gastric bug but we knew that was not the case. All day and night for 1 week she complained about her burning head and the second week she was so lost and confused she didn't have the energy to complain. Eventually after a scan she was correctly diagnosed and she had a drainage operation within 24 hours. They shaved a little patch of hair, cut the skin about 5" then drilled a small hole into the right side of the skull. They inserted saline and cleaned the inside. After surgery she had a pipe coming out of the hole with a bag attached for the blood to drain into. Had that about 3 days. Pipe came out abd after about 10 days in hospital the staples came out to. She has fully recovered now you cant actually tell she had any surgery. The cause was a medication she was on called Warfarin a blood thinner they use to thin bloodclots. Her blood got to thin causing her brain to bleed.

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Rob1822 said on 12 October 2010

My subdural hematoma started with headaches which I don’t normally suffer with, these became worse over weeks, I then started to see a prism at both sides of my vision, like looking through a kaleidoscope, the doctor and optician could find no sign of pressure on my eyes, the doctor initially thought Migraine, after eight weeks I was gray and pausing (unknown to me) for quite a few seconds when responding to questions I also had a slight turn on left eye. The doctor sent me for a CT scan which was delayed by a set of errors, by the time I had my scan I was semi conscious and vomiting, I have no recollection from the hospital car park to the look on the nurses face that had my CT image (panic) I was then taken to the main head injuries hospital and operated on at midnight, after a burr hole evacuation I woke up in the early hours feeling fine and got out of bed, then put straight back in by the nurse and told to stay there. I had some wild hallucinations for a couple of weeks, I was given an MRI scan and an angiogram inserted at my groin area to check all was well, thanks to the great work of the health professionals I made a full recovery. I still don’t know the cause as I never suffered any blow to the head or accident.

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