Is It a Bruise or a Hematoma?

Bruises and hematomas occur when blood leaks outside of an injured blood vessel after a trauma. There are many differences between them, including their appearance, symptoms, and healing time, as well as the types of blood vessels involved.

In this article, you'll learn how to distinguish bruises from hematomas. You'll also learn why they occur and what can be done to treat them.

What Is a Bruise?

Bruises, also known as ecchymosis, result from small leaks from small blood vessels like capillaries.

Those that occur under the surface of your skin are usually quite visible. The initial black and blue skin discoloration will change to a yellow, green, or light brown color within five to 10 days.

Bruises are flat, although mild swelling may be present. They can be tender to the touch.

Bruises can also form in deeper tissues, including muscles and bones. Though you won't see them, you will feel pain and soreness in the area of the injury.

Bruises usually heal on their own within a week or two. They rarely cause serious complications, but can if they are accompanied by additional injuries such as a fracture. For example, a black eye from a facial fracture may cause vision problems.

What Is a Hematoma?

Hematomas are larger bleeds that often involve larger blood vessels. With a hematoma, the leaking blood will pool and clot, causing a firm and tender mass.

Hematomas can develop deep within the body, such as in a muscle or in or around an internal organ. They can also form beneath the skin, on the scalp, nose, or ears, or under a toenail or fingernail.

When it is closer to the surface of the skin, the hematoma may appear as a painful red, black, or blue lump. As it breaks down, the skin will eventually change to a yellowish or brown color.

Unlike bruises, hematomas can cause serious harm. If they get large enough, hematomas may cause blood pressure to drop and can even lead to shock. Very large hematomas, like those within the wall of the abdomen, can cause organs to shift and affect how they function.

The most dangerous hematomas are in the brain and skull. With these, the blood can become trapped within the skull and put pressure on the brain. This can cause brain damage, coma, or death. Paralysis, seizures, and loss of consciousness are the most serious symptoms of a skull hematoma.

Healing time ranges from weeks to months, depending on the size and location of the hematoma.

Causes and Risk Factors

Bruises and hematomas both occur when a force—usually a blunt force—directly impacts the body, causing blood vessels to break open. Examples include falls, car accidents, and sports injuries.

Medical procedures, surgeries, and bone fractures can also cause bruises and hematomas.

There are certain factors that may increase a person's risk of bruises or hematomas:

• Older age
• Bleeding disorders, like hemophilia
• Thrombocytopenia (low platelet count)
• Alcoholism
• Liver disease
• Vitamin C or K deficiency
• Severe viral infection
• Blood cancer

Certain drugs can also increase the risk of bruises or hematomas:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin
• Blood thinners like heparin and Coumadin (warfarin)
  
• Corticosteroids, like prednisone
• Certain antibiotics
• Certain supplements like Ginkgo biloba, omega-3 fatty acids, and garlic

Diagnosis

Most of the time, doctors can diagnose a bruise or hematoma on the skin just by looking at it during a physical exam. For suspected bone bruises, an X-ray may be ordered to check for fractures.

In the case of an internal hematoma, including one in the skull or brain, an imaging test like a computed tomography (CT) scan or magnetic resonance imaging (MRI) is usually required.

Treatment

Milder bruises or hematomas are treated similarly. Larger or internal hematomas may require more active medical interventions.

Bruises and Superficial Hematomas

Bruises resolve on their own but may benefit from treatments like the RICE method (rest, ice, compression, and elevation) to speak the healing. This involves:

• Rest and elevate the area where the bruise/hematoma is to minimize swelling and ease discomfort.
• For the first day or two after the injury/trauma, apply a bag of frozen peas or an ice pack wrapped in a towel to the affected area for 10 to 15 minutes several times a day.
• Gently compress the injured area with an elastic bandage if swelling is present.

Hematomas on the skin may benefit from a similar approach, although a splint may be advised to keep an injured limb from moving and prevent the larger vessel from breaking open again.

Larger or Deeper Hematomas

Hematomas that are pressing on a nerve or blood vessel or causing tissue damage may require surgical drainage or removal. The drainage of any hematoma must occur relatively soon before the blood clots and forms a solid mass.

Bed rest and observation may be all that is needed for small skull hematomas.

For large skull hematomas, a procedure known as burr hole surgery may be used to drill a hole in the skull in order to drain the trapped blood. Severe cases may require a craniotomy, during which a piece of skull bone is temporarily removed to extract the trapped blood.

In both cases, a drain may be left in place for a couple of days while the patient is closely monitored in the hospital.

The treatment of internal hematomas elsewhere in the body, such as the back abdominal wall (retroperitoneum), may involve a watch-and-wait approach under observation or immediate surgical investigation.

Summary

Bruises and hematomas are usually caused by a traumatic injury. A key difference between the two is that bruises result from an injury to smaller blood vessels while hematomas result from injury to larger blood vessels.

While bruises rarely cause serious complications, hematomas can—particularly those in the skull or brain.

Most bruises and superficial hematomas can be diagnosed with a physical exam and treated with the RICE method. Larger or deeper hematomas may require imaging studies and surgery.

A Word From Verywell

Developing a small hematoma under your nail or a bruise on your shin may be uncomfortable and not look great, but know that it will eventually heal.

That said, be sure to seek out medical attention if your bruise or hematoma is very painful, associated with serious trauma, or you have signs of an associated skin infection (such as increased redness, warmth, or pus-like drainage).

If you find that you bruise easily or frequently, speak with your doctor. It's possible that an underlying medical condition or medication you are taking is to blame.