Signs and symptoms of an intracranial hematoma may be evident right after a blow to your head, or they may take several weeks or longer to appear. You may seem fine after a head injury, a period called the lucid interval. However, with time, pressure on your brain increases, producing some or all of the following signs and symptoms:
- Increasing headache
- Drowsiness and progressive loss of consciousness
- Unequal pupil size
- Slurred speech
- Increased blood pressure
As more blood fills your brain or the narrow space between your brain and skull, other signs and symptoms may become apparent, such as:
When to see a doctor
An intracranial hematoma can be life-threatening. Emergency medical treatment often is necessary.
Seek immediate medical attention after a blow to the head if:
- You lose consciousness
- You have any of the signs and symptoms that could indicate an intracranial hematoma
Signs and symptoms of intracranial hematoma may not be immediately apparent, so watch for subsequent physical, mental and emotional changes. For example, if someone seems fine after a blow to the head and can talk but then becomes unconscious, seek immediate medical care.
Also, even if you feel fine, ask someone to keep an eye on you. You may have memory loss after a blow to your head, so you may forget about it eventually. Someone you tell may be more likely to recognize the warning signs and get you prompt medical attention.
The cause of intracranial bleeding (hemorrhage) usually is a head injury, often resulting from automobile, motorcycle or bicycle accidents, falls, assaults, and sports injuries. Mild head trauma is more likely to cause a hematoma if you're an older adult, especially if you're taking an anticoagulant or antiplatelet drugs, such as aspirin. You can have a serious injury even if there's no open wound, bruise or other outward sign of damage.
A hematoma may occur as a subdural hematoma, an epidural hematoma or an intraparenchymal hematoma.
This occurs when blood vessels — usually veins — rupture between your brain and the outermost of three membrane layers that cover your brain (dura mater). The leaking blood forms a hematoma that compresses the brain tissue. If the hematoma keeps enlarging, a progressive decline in consciousness occurs, possibly resulting in death.
The three types of subdural hematomas are:
- Acute. This type is the most dangerous. It's generally caused by a severe head injury, and signs and symptoms usually appear immediately.
- Subacute. Signs and symptoms take time to develop, sometimes days or weeks after your injury.
- Chronic. The result of less severe head injuries, this type of hematoma may cause much slower bleeding, and symptoms can take weeks to appear. You might not recall injuring your head.
All three types require medical attention as soon as signs and symptoms appear, or permanent brain damage may result.
The risk of subdural hematoma is greater for people who:
- Take aspirin or anticoagulants daily
- Abuse alcohol
- Are elderly
Also called an extradural hematoma, this type occurs when a blood vessel — usually an artery — ruptures between the outer surface of the dura mater and the skull. Blood then leaks between the dura mater and the skull to form a mass that compresses the brain tissue.
Some people with this type of injury remain conscious, but most become drowsy or comatose from the moment of trauma. An epidural hematoma that affects an artery in your brain can be deadly unless you get prompt treatment.
This type of hematoma, also known as intracerebral hematoma, occurs when blood pools in the brain. After a head trauma, there may be multiple severe intraparenchymal hematomas.
The trauma that causes intraparenchymal hematomas often is responsible for so-called white matter shear injuries — torn axons in the brain's white matter. Axons carry electrical impulses, or messages, from the neurons in the brain to the rest of the body. When this connection is sheared, serious brain damage can result.
These steps may help to prevent or minimize head injury:
- Wear a helmet and make sure your kids wear helmets. Wearing an appropriate and properly fitted helmet when playing contact sports, bicycling, motorcycling, skiing, horseback riding, skating, skateboarding, snowboarding or doing any activity that could result in head injury can help prevent injury.
- Buckle your seat belt and make sure your kids are buckled in. Doing so anytime you drive or ride in a motor vehicle may prevent or minimize head damage in an accident.
- Protect young children. Always use properly fitted car seats, pad countertops and edges of tables, block stairways, tether heavy furniture or appliances to the wall to prevent tipping, and keep children from climbing on unsafe or unsteady objects.