Hematoma definition and facts
- A hematoma is a collection of blood outside of a blood vessel.
- There are several types of hematomas and they are often described based on their location. Examples of hematomas include subdural, spinal, under the finger or toenail bed (subungual), ear, and liver (hepatic).
- Some causes of hematomas are as pelvic bone fractures, fingernail injuries (subungual), bumps, passing blood clots, blood clot in the leg (DVT), blood cancers, and excessive alcohol use.
- Symptoms of hematomas depend upon their location and whether adjacent structures are affected by the inflammation and swelling associated with the bleeding and may include
- Treatment of a hematoma depends upon which organ or body tissue is affected.
- Superficial hematomas of the skin and soft tissue, such as muscle, may be treated with rest, ice, compression, and elevation (RICE). Heat may also be considered.
What is a hematoma?
A hematoma is an abnormal collection of blood outside of a blood vessel. It occurs because the wall of a blood vessel wall, artery, vein, or capillary, has been damaged and blood has leaked into tissues where it does not belong. The hematoma may be tiny, with just a dot of blood, or it can be large and cause significant swelling.
The blood vessels in the body are under constant repair. Minor injuries occur routinely and the body is usually able to repair the damaged vessel wall by activating the blood clotting cascade and forming fibrin patches. Sometimes the repair fails if the damage is extensive and the large defect allows for continued bleeding. If there is great pressure within the blood vessel, for example, a major artery, the blood will continue to leak through the damaged wall and the hematoma will expand.
Blood that escapes from within a blood vessel is very irritating to the surrounding tissue and may cause symptoms of inflammation including pain, swelling, and redness. Symptoms of a hematoma depend upon their location, their size, and whether they cause associated swelling or edema.
Hematomas may occur anywhere in the body. Regardless of how a hematoma is described or where it is located, it remains a collection of clotted blood outside of a blood vessel.
What causes a hematoma?
Trauma is the most common cause of a hematoma. When people think of trauma, they generally think of car accidents, falls, head injuries, broken bones, and gunshot wounds. Trauma to tissue also may be caused by an aggressive sneeze or an unexpected twist of an arm or leg. When a blood vessel is damaged, blood leaks into the surrounding tissue; this blood tends to coagulate or clot. The greater the amount of bleeding that occurs, the larger the amount of clot (hematoma) formation.
What conditions cause a hematoma?
Conditions that cause a hematoma include:
- Medications: Blood thinners or anticoagulation medications, including warfarin (Coumadin), aspirin, clopidogrel (Plavix), prasugrel (Effient), rivaroxaban (Xarelto), and apixaban (Eliquis) may increase the potential for spontaneous bleeding and for hematomas to expand because the body cannot efficiently repair blood vessels. This allows blood to continually leak through the damaged areas.
- Diseases or conditions that may decrease the number of platelets in the bloodstream (thrombocytopenia) or diminish their function: Viral infections (rubella, parvovirus, mumps, chickenpox, HIV, and hepatitis C), aplastic anemia, cancers from other organs, long-term alcohol abuse, and vitamin D deficiency may be associated with hematomas.
- Orthopedic injuries: Fractures are always associated with hematomas at the fracture site. Fractures of long bones such as the thigh (femur) and upper arm (humerus) can be associated with a significant amount of bleeding.
What are other conditions that cause hematomas?
- Pelvic bone fractures: These breaks can also bleed significantly since it takes a large amount of force to break these bones and nearby veins and arteries also are frequently damaged.
- Menstruation: During menstruation, blood can accumulate in the vagina as part of the normal menses and, instead of flowing out immediately, it may form small blood clots.
- Pregnancy: Vaginal bleeding and passing blood clots or hematomas while pregnant are not normal and are reasons to seek immediate medical attention.
- Labor and delivery: Passing blood clots after delivering a baby is relatively common.
What are the different types of hematomas?
Hematomas are often described based upon their location. The most dangerous hematomas are those that occur inside the skull. Because the skull is an enclosed container, anything that takes up space increases pressure within and potentially impairs the ability of the brain to function.
What are epidural and subdural hematomas?
Epidural hematomas occur because of trauma, often to the temple, where the middle meningeal artery is located. Bleeding accumulates in the epidural space, outside the "dura" which is the lining of the brain. Because of the way the dura is attached to the skull, small hematomas can cause significant pressure and brain injury.
Subdural hematomas also occur because of trauma but the injury is usually to the veins in the brain. This causes a slower leak of blood, which enters the "subdural" space below the dura. The space below the dura has much more room for blood to accumulate before brain function suffers. As people age, they lose some brain tissue and the subdural space is relatively larger. Bleeding into the subdural space may be very slow, gradually stop, and not cause acute symptoms. These “chronic” subdural hematomas are often found incidentally on computerized tomography (CT) scans as part of a patient evaluation for confusion or because another traumatic incident occurred. However, subdural hematomas may be large, cause associated brain swelling, and may be lethal.
What are intracerebral and scalp hematomas?
Intracerebral hematomas occur within the brain tissue itself. Intracerebral hematomas may be due to bleeding from uncontrolled high blood pressure, an aneurysm leak or rupture, trauma, tumor, or stroke.
Scalp hematomas occur on the outside of the skull, and often can be felt as a bump on the head. Because the injury is to the skin and muscle layers outside of the skull, the scalp hematoma itself cannot press on the brain.
What are ear and nasal hematomas?
Ear hematomas may occur if an injury causes bleeding to the outside helix or cartilage structure of the ear. Often called boxer's ear, wrestler's ear, or cauliflower ear, blood becomes trapped between the thin layer of skin and the cartilage itself. Since the ear cartilage gets its blood supply directly from the overlying skin, a hematoma can decrease blood flow causing parts of the cartilage to shrivel and die. This results in a bumpy, deformed outer ear called a "cauliflower ear."
What are intramuscular and subungual hematomas?
Intramuscular hematomas can be very painful due to the amount of swelling and inflammation. Some muscles are surrounded by tough bands of tissue. If enough bleeding occurs, the pressure within these compartments can increase to the point that "compartment syndrome" can occur. In this situation, the blood supply of the muscle is compromised and the muscle and other structures such as nerves can be permanently damaged. This is most commonly seen in the lower leg and forearm. Compartment syndrome may also be seen as a complication of fractures. This is a true surgical emergency and medical care should be accessed immediately if compartment syndrome is suspected. For the health care professional, one clue to think of the diagnosis is finding a patient whose pain is out of proportion to the physical findings.
Subungual hematomas are the result of crush injuries to the fingers or toes. Bleeding from a subungual hematoma occurs under the fingernail or toenail and since it is trapped, pressure builds causing pain. Trephination, or drilling a hole through the nail to remove the blood clot, relieves the pressure and resolves the injury. Over time, the nail repairs itself.
What are subcutaneous and intra-abdominal hematomas?
Subcutaneous hematomas are bruises and contusions of the skin (ecchymosis). These occur due to trauma or injuries to the superficial blood vessels under the skin. Individuals who take anticoagulant medication are more prone to subcutaneous hematomas.
Intra-abdominal hematomas and hemorrhage may be due to a variety of injuries or illnesses. Regardless of how the blood gets into the abdomen, the clinical finding is peritonitis (irritation of the lining of the abdomen). Hematomas may occur in solid organs such as the liver, spleen, or kidney. They may occur within the walls of the bowel, including the small intestine (duodenum, jejunum, and ileum) or the large intestine (colon). Hematomas may also form within the lining of the abdomen called the peritoneum or behind the peritoneum in the retroperitoneal space (retro=behind).
What are the symptoms of a hematoma?
Hematomas cause irritation and inflammation. Symptoms of a hematoma depend upon their location, and whether the size of the hematoma or the associated swelling and inflammation cause nearby structures to be affected.
The common symptoms of inflammation from hematoma include:
- pain, and
How does a hematoma resolve?
In general, superficial hematomas of the skin, soft tissue, and muscle tend to resolve over time. The initial firm texture of the blood clot gradually becomes more spongy and soft as the body breaks down the blood clot, and the shape changes as the fluid drains away and the hematoma flattens. The color changes from that of a purplish-blue bruise to yellow and brown as the blood chemicals gradually are metabolized and the hematoma resolves. Depending upon its location, the discolorations may travel through different tissue planes by gravity. For example, a forehead hematoma may cause bruising beneath the eyes and seems to travel to the neck as it resolves over time.
When should I call a doctor about a hematoma?
Most hematomas are due to minor trauma and the person is aware of the injury, knows what part of the body was injured, and can expect to recover with few problems.
Some hematomas may be more serious because of their location. Usually symptoms are caused by the nearby affected areas. Seek medical care in the following situations (this list is not exhaustive):
- A person with a head injury with accompanying headache, confusion, vomiting, slurred speech, muscle weakness, vision changes, or difficulty being aroused should seek immediate medical attention.
- People taking blood thinners are at increased risk for significant bleeding from even minor injuries. It is often wise for these people to seek medical attention if they are involved in even minor accidents or sustain minor injuries.
- Blood clots in the urine require prompt evaluation.
How is a hematoma diagnosed?
Hematomas of the skin and soft tissues, such as muscle and joints, are often diagnosed by physical examination alone.
For patients exhibiting signs of internal bleeding, the health care professional will decide what imaging modality is best to evaluate the situation. Plain X-rays may be needed to assess for bone fracture. Patients with significant head injury often require CT scans. Ultrasound is the testing modality of choice for females who are pregnant.
What is the treatment for a hematoma?
Hematomas of the skin and soft tissues are often treated with rest, ice, compression, elevation (RICE). Some health care professionals may advocate heat as another treatment alternative. The pain of a hematoma is usually due to the inflammation surrounding the blood and may be treated with over-the-counter pain medications. The choice of medication depends upon the underlying health of the patient. For those patients who are taking anticoagulation medications, ibuprofen is relatively contraindicated (not recommended) because of the risk of gastrointestinal bleeding. Patients with liver disease should not take over-the-counter acetaminophen. When in doubt, it is wise to ask the health care professional or pharmacist for a recommendation.
Treatment for hematomas involving other organs in the body depends upon what organ system is involved. In these cases, treatment will be tailored to the specific situation.
What are the complications of a hematoma?
Hematomas cause swelling and inflammation. Often the inflammation and swelling cause irritation of adjacent organs and tissues, and cause the symptoms and complications of a hematoma.
Can hematomas be prevented?
Accidents happen and most hematomas are inevitable once the trauma has occurred.
For patients taking anticoagulation medications, it is wise to avoid participating in events with high risk of injury. For patients taking warfarin (Coumadin), it is important to make certain that the dosing is appropriate and the blood is not thinned excessively.
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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.