What are hematomas?

Causes and Symptoms

A hematoma is caused by blood leakage through the wall of an artery, capillary, or vein; subsequent pooling in surrounding tissue; and resultant coagulation in a semisolid mass. This leakage may occur spontaneously due to fragility of a vessel wall or due to an aneurysm. Leakage may also occur posttrauma due to events ranging from a violent sneeze to bodily injury. Symptoms usually consist of localized edema, inflammation, and pain.

A hematoma can occur anywhere along the circulatory system pathway and may be given a descriptive label indicative of its location. Superficial hematomas include aural, intramuscular, scalp, septal, subcutaneous, and subungual hematomas. An aural (ear) hematoma is a blood mass that accumulates between the ear cartilage and the periphondrium (connective tissue) as a result of blunt force trauma to the external ear. Symptoms include ecchymosis (discoloration to the area) and swelling. An intramuscular hematoma is a blood mass that accumulates within a muscle, often in the forearm or lower leg, as a result of blunt force trauma that leaves skin intact but damages muscle fibers and connective tissue. Symptoms include ecchymosis and swelling. A scalp hematoma is a blood mass that accumulates in the skin and muscle layer covering the skull as a result of head injury. Although not usually serious, it nonetheless could be indicative of bleeding within the skull. A septal hematoma is a blood mass that accumulates
in the nasal septum, usually in conjunction with a broken nose or injury to nearby soft tissue. Symptoms include nasal congestion, septal swelling, and resultant difficulty breathing. A subcutaneous hematoma is a blood mass that accumulates under the skin as a result of damage to superficial blood vessels. It occurs more frequently to those who take anticoagulants. Symptoms include ecchymosis and swelling. A subungual hematoma is a blood mass that accumulates under the nail plate of a finger or toe. Symptoms include pain due to pressure buildup in the nail bed.

Internal hematomas include cranial, fracture site, and intraabdominal hematomas. Cranial hematomas can be epidural, subdural, or intracerebral; all are potentially life threatening. An epidural hematoma (also called extradural hematoma) is a blood mass that accumulates in the epidural space (inside the skull but outside the dura mater, the membrane that covers the brain), often as a result of damage to the middle meningeal artery, located in the temple area, following skull fracture. Symptoms include asthenia (weakness), confusion, dizziness, drowsiness, nausea and vomiting, severe headache, unmatched pupil size, and often intermittent loss of consciousness.

An acute, subacute, or chronic subdural hematoma
(also called subdural hemorrhage) is a blood mass that accumulates in the subdural space (inside the dura mater but outside the brain tissue) as a result of damage to cerebral veins, most often due to head injury. Symptoms in adults include asthenia, balance difficulties, confusion or lethargy, headache, nausea and vomiting, seizures, speech difficulties, and visual disturbances. Symptoms in infants include bulging fontanelles, high-pitched crying, increased head circumference, seizures, and vomiting. Symptom onset is more gradual than for epidural hematoma due to a slower leakage rate for venous blood compared to arterial blood and a larger space for blood to fill before pressure buildup is sufficient to affect brain function. For an acute-onset hematoma, which is associated with the highest rate of death or permanent injury, symptoms usually occur immediately after severe head injury. For a subacute-onset hematoma, symptoms may occur days or weeks after injury occurrence. For a chronic-onset hematoma, symptoms may occur weeks after a less severe head injury.

An intracerebral hematoma (also called intraparenchymal hematoma) is a blood mass that accumulates in the brain tissue as a result of aneurysm, anticoagulant use, arteriovenous malformation, autoimmune diseases, bleeding disorders, brain tumor, drug abuse (amphetamines, cocaine), encephalitis (central nervous system
infection), or uncontrolled chronic hypertension. It may be accompanied by shear injury—tearing of the axon portion of the cranial nerves located in the substantia alba (white matter of the brain)—resulting in severe brain damage due to loss of ability to transmit neural impulses from the brain to the body. A fracture site hematoma is a blood mass that accumulates near a fracture, especially that of the femur (thigh), humerus (upper arm), or pelvis, all of which can result in significant internal hemorrhage. An intraabdominal hematoma is a blood mass that accumulates somewhere within the abdomen—in any of the abdominal organs, in any abdominal component of the gastrointestinal tract, in the peritoneum, or in the retroperitoneal space.

Treatment and Therapy

Initial treatment of superficial hematomas consists of rest-ice-compression-elevation (RICE) of the affected area, if possible, as well as oral administration of nonsteroidal anti-inflammatory drugs (NSAIDs) or other analgesics, if pain management is required.

For an aural hematoma, more aggressive treatment may be necessary due to the potential compromise of blood supply and subsequent cartilage atrophy resulting in a deformity of the pinna (outer ear) that is commonly known as cauliflower ear. Treatment consists of lancing and draining the hematoma followed by application of a compression bandage to enable reperfusion of the cartilage and to prevent hematoma reformation. This bandage is usually removed after three to seven days.

For intramuscular hematoma, more aggressive treatment may be necessary due to the potential compromise of blood supply and subsequent damage to the muscle, connective tissues, and nerves, a condition known as compartment syndrome. It most commonly occurs in muscles of the forearm and lower leg. Treatment consists of surgical intervention to drain the hematoma.

For septal hematoma, more aggressive treatment may be necessary due to the potential compromise of blood supply and subsequent cartilage atrophy resulting in perforation of the septum. Treatment consists of lancing and draining the hematoma followed by application of a gauze sponge or cotton ball in the nasal cavity.

For subungual hematoma, more aggressive treatment may be necessary to relieve pressure between the nail plate and the nail bed. Treatment consists of trephination (hole boring) of the nail plate and drainage of the hematoma.

Cranial hematomas (epidural, subdural, and intracerebral) are potentially life threatening and require immediate medical attention at the onset of signs or symptoms due to the risk of irreversible brain damage and possible death. Administration of anticonvulsant medication may be necessary to control or prevent seizures, and administration of corticosteroid medication may be necessary to reduce cerebral edema (brain swelling).

For epidural hematoma, diagnosis of increased intracranial pressure and location of hematoma are confirmed via computed tomography (CT) scan. Treatment consists of prompt surgical intervention to drain or remove the hematoma. For acute, subacute, and chronic subdural hematoma, diagnosis and location of the hematoma are confirmed via CT scan or magnetic resonance imaging (MRI) scan. Increased risk factors include advanced age, alcohol abuse, and daily use of anticoagulants, anti-inflammatory medication, or aspirin. Treatment consists of prompt surgical intervention to drain or remove the hematoma.

For intracerebral hematoma, diagnosis of increased intracranial pressure and location of hematoma are confirmed via CT scan or MRI scan. Treatment may consist of surgical intervention to drain or remove the hematoma.

Perspective and Prospects

Although intrinsic factors—such as aneurysm, arteriovenous malformations, autoimmune diseases, bleeding disorders, brain tumor, encephalitis, or uncontrolled chronic hypertension—and extrinsic factors—such as anticoagulant use, alcohol abuse, or drug abuse (amphetamines, cocaine)—may increase the likelihood of hematoma formation, the most common cause is trauma. Minor traumas, ranging from a violent sneeze to a mild sports injury, as well as major traumas, including car accidents and severe falls, all have the potential to cause hematoma formation.

While the size, type, and severity of hematomas vary according to location and causality, a common complication is infection risk as a result of the colonization of bacteria in stagnant blood. Attenuation or avoidance of complications may be achieved by early diagnosis and, if warranted, prompt medical treatment.

As is the case with all undesirable medical conditions, prevention is preferable to treatment. Although trauma prevention may not always be possible, risk may be minimized via lifestyle choices and proper use of safety equipment.

Bibliography

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