While many hematomas are relatively harmless, some can indicate a more serious medical problem.
Anyone who has sustained an injury in an accident or received a blow to the head should speak to a doctor about the signs of an internal hematoma.
What is a hematoma?
A hematoma is an area of blood that collects outside of the larger blood vessels.
The term hematoma describes an area of blood that collects outside of the larger blood vessels. Hematomas are commonly due to injuries or trauma in the area.
An injury can cause blood vessel walls to break, allowing blood to make its way into the surrounding tissue.
Hematomas may occur in any blood vessel, including veins, arteries, and capillaries. The location of the hematoma may change its nature.
A hematoma is similar to a hemorrhage, but a hemorrhage refers to ongoing bleeding while the blood in a hematoma has typically already clotted.
The type of hematoma depends on where it appears in the body. The location may also help determine how potentially dangerous it is.
- Ear hematoma: An aural or ear hematoma appears between the cartilage of the ear and the skin on top of it. It is a common injury in wrestlers, boxers, and other athletes who regularly sustain blows to the head.
- Subungual hematoma: This hematoma appears under the nail. It is common in minor injuries, such as accidentally hitting a finger with a hammer.
- Scalp hematoma: A scalp hematoma typically appears as a bump on the head. The damage is to the external skin and muscle, so it will not affect the brain.
- Septal hematoma: Usually the result of a broken nose, a septal hematoma may cause nasal problems if a person does not receive treatment.
- Subcutaneous hematoma: This is a hematoma that appears just under the skin, typically in the shallow veins close to the surface of the skin.
- Retroperitoneal hematoma: This hematoma occurs inside the abdominal cavity but not within any organs.
- Splenic hematoma: This type of hematoma appears in the spleen.
- Hepatic hematoma: A hepatic hematoma occurs in the liver.
- Spinal epidural hematoma: This term refers to a hematoma between the lining of the spinal cord and the vertebrae.
- Intracranial epidural hematoma: This type of hematoma occurs between the skull plate and the lining on the outside of the brain.
- Subdural hematoma: A subdural hematoma occurs between the brain tissue and the internal lining of the brain.
Image credit: Birdies100, 2010
Image credit: Klaus D. Peter, 2012
Injuries and trauma are the most common causes of hematomas. Any damage to the walls of the blood vessels may cause blood leakage. This blood pools as it escapes the blood vessel, causing a hematoma.
Injuries do not have to be severe to cause hematomas. People may experience a hematoma under their toenail from a simple injury, such as stubbing their toe.
More significant injuries, such as those sustained from vehicle crashes, falling from a height, or an aneurysm can also cause severe hematomas.
Some surgical procedures, including medical, dental, or cosmetic operations, may lead to a hematoma as they can damage nearby tissues and blood vessels.
Some blood thinners may also increase the risk of hematomas. People who regularly take aspirin, warfarin, or dipyridamole (Persantine) may be more likely to experience bleeding problems, including hematomas.
A hematoma can also appear without any identifiable cause.
For more superficial hematomas, symptoms include:
- inflammation and swelling
- tenderness in the area
- warmth in the skin surrounding the hematoma
Internal hematomas may be more difficult to recognize. Anyone who has been in an accident or sustained a serious injury should regularly check in with a doctor to screen for hematomas.
Hematomas in the skull may be particularly dangerous. Even after seeing a doctor about an injury, it is essential to keep an eye out for new symptoms, such as:
- a severe, worsening headache
- uneven pupils
- difficulty moving an arm or leg
- hearing loss
- difficulty swallowing
- loss of consciousness
Symptoms may not present immediately, but they usually appear within the first few days. The authors of a 2014 study noted that the symptoms of subdural hematomas tend to occur within 72 hours of the injury.
Bruise vs. hematoma
Bruises are not serious, typically lightening or turning yellow before fading completely.
The discoloration and tenderness in the affected area tend to make people believe that hematomas and bruises are the same.
A bruise develops when blood leaks from smaller blood vessels, causing a purple, blue, or darkened spot to appear on the skin. The bruise changes color as it heals, typically lightening or turning yellow before fading completely. Bruises generally are not serious.
In contrast, a hematoma is a leakage from a larger blood vessel. The mark that it leaves might be dark blue or black, but it can also cause significant redness. More severe traumas cause hematomas, which may be serious and require medical treatment.
Most bruises heal on their own without the need for treatment. Severe bruises are rare, but they may damage the inner tissues or organs and require treatment to prevent infection.
In some cases, a hematoma will not require treatment. The body will usually reabsorb the blood from the hematoma over time.
To manage a hematoma under the skin, nail, or other soft tissue, a person should rest the injured area and apply an ice pack wrapped in a towel to reduce any pain or swelling.
It may help to wrap or splint the area around the hematoma to keep the blood vessel from reopening as it heals. A doctor will give a person specific instructions on how to do this if it is necessary.
Doctors may recommend some over-the-counter or prescription pain relievers if the injury is painful. They will usually advise a person to avoid certain pain relievers, such as aspirin, which thin the blood and may make the hematoma worse.
Sometimes, a hematoma may require surgical drainage. Surgery may be more likely if the blood is putting pressure on the spinal cord, brain, or other organs. In other cases, doctors may want to drain a hematoma that is at risk of infection.
Surgical treatment may not be necessary in all cases, even when the hematoma is inside the skull. For example, in a 2015 study of people with a subdural hematoma, the authors noted that the majority received conservative treatment. Only 6.5 percent of these individuals required surgical treatment at a later stage.
In rare cases, the hematoma may carry on growing as the damaged blood vessel continues to let out more blood. The result is a mix of old and new blood that doctors will need to remove completely.
An untreated hematoma can sometimes cause complications.
For instance, a hematoma in the brain may be difficult to discover if a person does not receive specific tests. They may experience symptoms such as a lasting headache, dizziness, or slurred speech.
Anyone who has had an injury to the head or a severe injury elsewhere should see a doctor.
When to see a doctor
Many hematomas are simple. A hematoma under the nail or skin may be painful, but it will not usually cause complications.
If a hematoma is especially painful, it is best to seek medical attention. A doctor can provide tips on wrapping or bracing the area. It is also a good idea to see a doctor if the area shows signs of infection, such as discoloration, swelling, and feeling warm to the touch.
Anyone who has had a head injury should see a doctor regularly to report any symptoms. A doctor may order imaging scans if they suspect a hematoma inside the skull.
Likewise, anyone who has been involved in a serious accident, such as a car crash or falling from a height, should regularly check in with their doctor. After the initial inflammation from the injuries goes down, doctors may want to check for bruising or hematoma affecting the internal tissues and organs.
Hematomas can look frightening, but proper treatment can help ensure that they do no lasting damage.
People can manage minor hematomas, such as those in the ear or under the nail, at home with conservative treatments.
Anyone who has sustained a head injury, been in an accident, or developed a hematoma that shows signs of infection should see a doctor. With a swift diagnosis and the proper treatment, most hematomas resolve without complications.