What Is a Hematoma and What Causes It?

If you are involved in an accident in Nebraska, you may be diagnosed with an injury known as a hematoma. A hematoma forms when trauma ruptures or damages blood vessels, causing blood to leak and pool outside the vessels in surrounding tissue. Depending on the location and severity, a hematoma can range from a minor bruise to a life-threatening emergency — and recognizing the warning signs quickly can be the difference between full recovery and permanent injury.

For accident victims, understanding what a hematoma is, what types require urgent medical attention, and how this injury affects the value of a personal injury claim is essential to protecting both your health and your legal rights.

What Is a Hematoma?

A hematoma is a collection of blood outside of blood vessels, caused by trauma that breaks vessel walls and allows blood to escape into surrounding tissue. Unlike a simple bruise — which involves minor capillary bleeding close to the skin surface — a hematoma typically involves larger blood vessels and produces a more defined pool of blood that can create pressure, swelling, and pain in the affected area.

Car accidents, falls, and other significant trauma are among the most common causes of serious hematomas. The blunt force of a collision, impact with a steering wheel, airbag deployment, or being struck by another object can all generate sufficient force to rupture blood vessels deep inside the body — including within the skull, where hematomas become especially dangerous.

Types of Hematomas Commonly Seen After Car Accidents

Subdural Hematoma

A subdural hematoma occurs when blood collects between the brain and the outermost protective membrane (the dura mater). It is caused by tearing of the bridging veins — blood vessels that bridge the brain surface and the dura. Subdural hematomas are among the most serious traumatic brain injuries associated with car accidents. Blood accumulates in the subdural space, creating pressure on the brain that can cause progressive neurological deterioration. Symptoms may develop immediately after impact or be delayed for hours or even days, making them especially dangerous — a person may appear fine initially and then rapidly worsen.

Epidural Hematoma

An epidural hematoma occurs when blood collects between the skull and the dura mater, typically from arterial bleeding. Epidural hematomas are most often caused by a direct blow to the head that fractures the temporal bone and ruptures the middle meningeal artery. They are a neurosurgical emergency — the classic presentation includes a brief loss of consciousness, a “lucid interval” during which the person seems fine, followed by rapid neurological deterioration as the expanding blood pool compresses the brain. Without prompt surgical intervention, an epidural hematoma can be fatal.

Intracerebral Hematoma

An intracerebral hematoma is a bleeding event within the brain tissue itself. These can result from direct trauma or from the shearing forces of a high-speed collision that damage blood vessels deep within the brain. Intracerebral hematomas are associated with the most severe traumatic brain injuries and often produce immediate neurological symptoms including paralysis, speech impairment, and loss of consciousness.

Subgaleal Hematoma

A subgaleal hematoma occurs between the skull and the scalp. This type is common after head impacts and typically presents as a soft, fluctuant swelling on the scalp. While usually less dangerous than intracranial hematomas, large subgaleal hematomas can result in significant blood loss, particularly in children.

Subcutaneous and Soft Tissue Hematomas

These are the most common type seen after car accidents — localized collections of blood just under the skin surface or within muscle tissue. They typically present as painful, firm, discolored swellings at the site of impact. While often less medically dangerous than intracranial hematomas, large soft tissue hematomas can indicate significant underlying trauma and may be associated with fractures or internal organ injuries.

Organ and Abdominal Hematomas

Blunt abdominal trauma in car accidents can cause hematomas involving the liver, spleen, or kidneys. Splenic hematomas in particular can be life-threatening — the spleen’s highly vascular structure makes it prone to rupture following blunt force trauma, and a delayed splenic rupture (hours or days after the initial injury) can cause sudden, severe internal bleeding without warning.