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 the blood vessels affected, appearance and symptoms, and healing time.

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

What Is a Bruise?

Bruises result from small leaks from small blood vessels, like capillaries.

When they occur under the surface of your skin, they are usually quite visible. Initial black and blue skin discoloration changes to a yellow, green, or light brown color within five to 10 days.

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

Bruises can also form in deeper tissues, like those that make up 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 after the bleeding stops, which takes a week or two. They rarely cause dangerous complications, but can if they are extensive or accompanied by an additional problem. For example, a black eye from a facial fracture may cause vision problems.

What Is a Hematoma?

Hematomas are larger bleeds and often involve larger blood vessels. With a hematoma, the leaking blood pools and clots to form a firm and tender mass.

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

When closer to the surface of the skin, the hematoma appears as a painful lump that is initially red, black, or blue.

As hematomas break down and absorb the firm collection of blood, they eventually change to yellow or brown.

Hematomas can become quite large and collect enough blood to cause low blood pressure and shock.

Very large hematomas, like those that develop within the muscular wall of the abdomen, can cause organs to shift or stop working properly.

Healing time for a hematoma can range from weeks to months.

Hematoma in the Skull

The most dangerous types of hematomas affect the brain and skull.

Since the skull is a closed-off area, blood can become trapped inside the skull and put pressure on the brain. This may result in brain damage, coma, or death.

There are two types of skull hematomas:

• Epidural hematoma: Blood collects between the skull and the brain's protective lining, called the dura.
• Subdural hematoma: Blood collects between the actual brain tissue and the dura.

Symptoms of a potential intracranial hematoma include:

• Persistent headache
• Loss of memory, confusion, or disorientation
• Sleepiness
• Dizziness and loss of balance
• Nausea and vomiting 
• Slurred speech
• Vision changes
• Weakness on one side of the body

Paralysis, seizures, and loss of consciousness are the most serious symptoms of a skull hematoma.

Causes and Risk Factors

Both bruises and hematomas occur when a force (usually a blunt one) directly strikes the skin causing one or more blood vessels to break open.

Trauma from car accidents, sports injuries, falls, and medical procedures or surgeries are typical causes. Orthopedic injuries and fractures (broken bones) may also cause bruising or a hematoma.

There are also factors that increase a person's chances of forming bruises or hematomas. One major one is advanced age.

As you age, your skin thins and becomes more fragile, making you more prone to bruising. Likewise, older individuals are at a higher risk for developing hematomas, especially subdural hematomas, even with a minor injury.

There are also various health problems that increase your risk of bruising or developing hematomas.

In their own unique ways, these conditions impair the ability of injured blood vessels to stop bleeding:

• Bleeding disorders, such as hereditary hemorrhagic telangiectasia, hemophilia, or von Willebrand disease 
• A low platelet count (thrombocytopenia)
• Alcohol use disorder
• Liver disease
• Vitamin K or C deficiency
• Severe viral infection or blood cancer

Certain medications can also make you more likely to bruise or develop a hematoma, such as:

• Aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs)
• Blood thinners like heparin, Coumadin (warfarin), and direct oral anticoagulants
• Certain antibiotics
• Corticosteroids, both those used on the skin (topical) and for the whole-body (systemic)
• Certain herbal products or supplements like Ginkgo biloba, omega-3 fatty acids, and garlic

Diagnosis

Most of the time, doctors can diagnose a bruise or hematoma just by looking at it during a physical examination.

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

For suspected bone bruises, an X-ray may be ordered to evaluate for fractures. An MRI may be used to examine the bruise or to check for microfractures.

Treatment

Bruises resolve on their own, but may benefit from treatment to speed-up healing and reduce discomfort.

For the vast majority of bruises and for small, close-to-the-surface hematomas, treatment involves the R.I.C.E method (rest, ice, compression, elevation).

Specifically, the steps of this method include:

• 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.

For any discomfort or pain associated with your bruise or hematoma, your doctor may recommend taking Tylenol (acetaminophen). You will probably be asked to avoid taking NSAIDs, like Motrin (ibuprofen), as they can worsen the bruising/bleeding.

Hematomas that are pressing on a nerve or blood vessel or causing tissue damage may require surgical drainage or removal. Keep in mind that drainage of any hematoma must occur relatively soon after it has formed before the liquid blood becomes more firm and solid.

Surgery may also be needed to repair any related organ damage, if applicable.

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

For large skull hematomas, the surgeon may need to drill a hole in the patient's skull to drain the trapped blood—what's known as burr hole surgery. The drain may be left in place for a couple of days while the patient is being closely monitored in the hospital.

Alternatively, a craniotomy may be performed. During this surgery, a part of the skull bone is temporarily taken out in order to remove the trapped blood. A drain may be placed for a couple of days to help get rid of excess blood or fluid.

Summary

Bruises and hematomas are caused by trauma or a bodily injury. A key difference between them is that bruises result from injury to smaller blood vessels whereas hematomas result from injury to larger ones.

Where bruises remain flat, hematomas form firm lumps or masses because of the blood that pools and becomes trapped.

Hematomas also generally take longer to heal than bruises and can be dangerous if they form on the skull or any internal organ.

Most bruises and superficial hematomas can be diagnosed during a physical exam and treated with the R.I.C.E. method. Skull, extensive, or deeper hematomas may require imaging 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 (e.g., pus draining, increased redness, or warmth).

Lastly, if you find that you are bruising easily or frequently, it's a good idea to talk with your doctor. It's possible that an underlying medical condition or medication you are taking is to blame.