Subdural Hematoma

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is subdural hematoma?

A subdural hematoma is a collection of blood underneath the dura mater, the tough outer layer of the meninges, the membranes that surround the brain and spinal cord. The bleeding comes from small veins that cross over the brain, between it and the dura mater. An enlarging subdural hematoma can push against the brain, leading to tissue compression and displacement of vital structures.

Subdural hematomas are almost always caused by head trauma, although in rare cases, they can occur spontaneously. Serious head injuries can cause acute subdural hematomas, in which the torn veins bleed rapidly into the subdural space, and pressure on the brain builds quickly. Acute subdural hematomas can occur in any age group. Young children with acute subdural hematomas due to nonaccidental trauma often harbor other signs of physical abuse.

Chronic subdural hematomas are more common in the elderly, in whom the veins in the subdural space are stretched due to atrophy, or shrinkage, of the brain. Seemingly minor injuries can cause these fragile veins to break. Blood accumulates and pressure builds more slowly, so symptoms may take days or weeks to occur. Sub-acute subdural hematomas, in which the bleeding is faster than in a chronic subdural hematoma, but not as fast as that in an acute subdural hematoma, can also occur.

Symptoms of subdural hematomas include confusion, headache, movement difficulties, loss of sensation, visual changes, speech difficulties, seizures, lethargy, vomiting, and loss of consciousness. In infants, the fontanelles (“soft spots”) may bulge, the head may increase in size, cries may be high pitched or shrill, and irritability or feeding difficulties may occur. Emergency surgery may be required to relieve pressure on the brain and medications may be given to reduce brain swelling or control seizures.

A subdural hematoma is always a medical emergency and needs to be treated as quickly as possible to save as much brain tissue as possible. Seek immediate medical care (call 911) for significant head trauma, severe headache, confusion, loss of sensation or the ability to speak, lethargy, loss of consciousness or alertness, or symptoms such as shrill, high-pitched cries, poor feeding, unusual irritability, or changes in head shape or size in an infant.

What are the symptoms of subdural hematoma?

Symptoms of subdural hematomas can be related to loss of motor or sensory function, impaired thought processes, or changes in level of consciousness. Other symptoms can include pain, nausea and vomiting, and seizures. Infants may exhibit unusual irritability, poor feeding, or lethargy. Their cries may be high pitched and changes in their head size or shape may be apparent.

Common symptoms of subdural hematoma

Common symptoms of subdural hematoma include:

  • Confusion or loss of consciousness for even a brief moment

  • Difficulty with memory, thinking, talking, comprehension, writing or reading

  • Headache

  • Impaired balance and coordination

  • Loss of sensation

  • Loss of vision or changes in vision

  • Seizures

  • Weakness

Serious symptoms that might indicate a life-threatening condition

Subdural hematoma is always life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

  • Change in level of consciousness or alertness such as passing out or unresponsiveness

  • Change in mental status or sudden behavior change such as confusion, delirium, lethargy, hallucinations or delusions

  • Garbled or slurred speech or inability to speak

  • Head trauma

  • High-pitched, shrill cries in an infant or small child

  • Irritability, fussiness, poor feeding, and unusually poor sleeping in infants and young children

  • Paralysis or inability to move a body part

  • Seizures

  • Severe headache

  • Sudden change in vision, loss of vision, or eye pain

What causes subdural hematoma?

Subdural hematomas are almost always caused by head trauma. Serious head injuries can cause acute subdural hematomas. In the elderly, chronic subdural hematomas may result from more minor head injuries. On rare occasions, subdural hematomas can form spontaneously.

What are the risk factors for subdural hematoma?

A number of factors increase the risk of developing subdural hematoma. Not all people with risk factors will get subdural hematoma. Risk factors for subdural hematoma include:

  • Bleeding disorders

  • Chronic alcohol abuse

  • Extremes of age (infants and the elderly)

  • Repeated falls or head injury

  • Use of medications that thin the blood such as anticoagulants, antiplatelet agents, or aspirin

Reducing your risk of subdural hematoma

You may be able to lower your risk of subdural hematoma by:

  • Avoiding falls

  • Wearing a seatbelt, helmet, or hard hat when appropriate

How is subdural hematoma treated?

Treatment of a subdural hematoma may require emergency surgery and use of medications to decrease brain swelling and control seizures.

Common treatments of subdural hematoma

Common treatments of subdural hematoma include:

  • Anticonvulsants to control seizures

  • Diuretic medications to reduce brain swelling

  • Rehabilitation to help strengthen the body and improve functional ability

  • Surgery to relieve pressure inside the skull

  • Surgery to remove blood clot

What are the potential complications of subdural hematoma?

Complications of untreated subdural hematoma can be serious, even life threatening in some cases. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of subdural hematoma include:

  • Cognitive impairment

  • Disability

  • Loss of vision or changes in vision

  • Paralysis or weakness

  • Permanent loss of sensation

  • Personality changes

  • Unconsciousness and coma

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 20
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. NINDS traumatic brain Injury information page. National Institute of Neurological Disorders and Stroke.
  2. Subdural hematoma. PubMed Health, a service of the NLM from the NIH.
  3. Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.