Hematoma

Hematoma is generally defined as a collection of blood outside of blood vessels. Most commonly, hematomas are caused by an injury to the wall of a blood vessel, prompting blood to seep out of the blood vessel into the surrounding tissues. A hematoma can result from an injury to any type of blood vessel (artery, vein, or small capillary). A hematoma usually describes bleeding which has more or less clotted, whereas a hemorrhage signifies active, ongoing bleeding.

Hematoma is a very common problem encountered by many people at some time in their lives. Hematomas can be seen under the skin or nails as purplish bruises of different sizes. Skin bruises can also be called contusions. Hematomas can also happen deep inside the body where they may not be visible. Hematomas may sometimes form a mass or lump that can be felt. Sometimes hematomas are named based on their location. Some examples include:

• Subdural hematoma: a hematoma between the brain tissue and the inside lining of the brain
• Spinal epidural hematoma: a hematoma between spinal vertebrae and the outside lining of the spinal cord
• Intracranial epidural hematoma: a hematoma between the skull and the outside lining of the brain
• Subungual hematoma: a hematoma under the nail
• Intra-abdominal, peritoneal, or retroperitoneal hematoma: a hematoma inside the abdominal cavity
• Ear or aural hematoma: a hematoma between the ear cartilage and overlying skin
• Splenic hematoma: a hematoma within the spleen
• Hepatic hematoma: a hematoma within the liver

Most hematomas resolve spontaneously over time as the blood debris is removed and the blood vessel wall is repaired by the body’s repair mechanisms. Other times, surgically removing or evacuating the blood in a hematoma becomes necessary based on its symptoms or location.

The most common cause of a hematoma is injury or trauma to blood vessels. This can happen as a result of any damage to blood vessels that can disrupt the integrity of the blood vessel wall. Even minimal damage to a small blood vessel can result in a hematoma. For example, a hematoma under a nail (subungual hematoma) can simply occur from minor trauma to the nail or from a light stroke against an object.

More severe traumas can cause more major hematomas. Falling from a height or getting into a motor vehicle accident can cause noticeably large bleeding under the skin or inside body cavities (chest or abdomen).

Other types of tissue injury causing a hematoma can result from surgeries of any sort, invasive medical or dental procedures (for example, biopsies, incision and drainage, cardiac catheterization), and injection of medications (for example, insulin, blood thinners, vaccines). Because these procedures damage nearby tissues and blood vessels, often hematomas may form around the site of the procedure.

Occasionally, a hematoma may happen spontaneously without any identifiable cause or recollection of any specific injury or trauma.

Certain blood thinner medications can increase the risk of hematoma formation. People who take medications such as Coumadin (warfarin), Plavix (clopidogrel), aspirin, Persantine (dipyridamole)), or aspirin-containing products (like Alka Seltzer) may develop a hematoma much easier and with less severe injury to their blood vessels than other people. These medications impair the clotting ability of the blood and therefore, minor damage to a blood vessel becomes more difficult to repair, resulting in hematoma formation.

Other common medications and supplements that may increase bleeding tendencies include:

• vitamin E,
• nonsteroidal anti-inflammatory drugs or NSAIDs such as ibuprofen (Motrin, Advil, Aleve),
• garlic supplements, and
• Ginkgo biloba.

In summary, a list of medications causing excess bleeding include:

• warfarin (Coumadin),
• clopidogrel (Plavix),
• aspirin,
• aspirin-containing products (Alka Seltzer),
• dipyridamole (Persantine),
• vitamin E,
• NSAIDs, for example, ibuprofen, Motrin, Advil, Aleve,
• garlic supplements, and
• Ginkgo biloba.

There are also certain medical conditions that may pose an additional risk for developing hematomas. Individuals with the following conditions are potentially at a higher risk for hematomas:

• chronic (long standing) liver disease,
• excessive alcohol use,
• bleeding disorders (such as hemophilia and Von Willebrand disease),