Head injuries can lead to bleeding within the skull, known as hematomas. These internal bleeds are medical emergencies that demand immediate attention. They can rapidly cause significant pressure on the brain, making it important to recognize when urgent medical care is necessary.
Understanding Brain Hematomas
A brain hematoma is a collection of blood within the skull, resulting from trauma that damages blood vessels. As blood collects, it exerts pressure on brain tissue. This increased intracranial pressure can disrupt normal brain function and lead to severe neurological damage if not promptly addressed.
Epidural Hematoma
An epidural hematoma occurs when blood gathers between the dura mater, the tough outer membrane covering the brain, and the inner surface of the skull. This hematoma is typically caused by a forceful head impact, often resulting in a skull fracture. The fracture can tear an underlying artery, leading to rapid blood accumulation. Individuals may experience a “lucid interval,” appearing relatively normal immediately after injury, only to rapidly deteriorate hours later as the hematoma expands.
Subdural Hematoma
A subdural hematoma forms when blood collects beneath the dura mater but above the arachnoid mater. These hematomas arise from the tearing of bridging veins.
Unlike epidural hematomas, subdural hematomas are classified by symptom timeline: acute, subacute, or chronic. Acute forms develop rapidly after severe trauma, with symptoms within hours. Subacute hematomas appear within days to weeks, while chronic forms can take weeks or months, often after a minor head injury.
This delayed presentation is common in older adults or those on blood-thinning medications, where brain atrophy may allow more blood accumulation before symptoms become noticeable.
Key Differences and Severity
Epidural and subdural hematomas have distinct characteristics. Their primary difference is anatomical location: epidural hematomas form between the skull and the dura, while subdural hematomas develop between the dura and the arachnoid membrane. The source of bleeding also differs; epidural hematomas stem from arterial tears, leading to high-pressure bleeding, whereas subdural hematomas involve venous tears.
Symptom onset and progression also distinguish them. Epidural hematomas often present with rapid deterioration after a “lucid interval” due to fast arterial blood accumulation. Subdural hematomas have variable onset, from acute, life-threatening presentations to chronic, delayed symptoms. An acute subdural hematoma can be as devastating as an epidural hematoma, causing rapid neurological decline. Chronic subdural hematomas, though slower, can still cause significant neurological impairment if undiagnosed.
Both types of hematomas exert pressure on the brain, but determining which is “worse” is complex. An epidural hematoma’s rapid expansion makes it acutely dangerous, requiring immediate surgical intervention. However, a large acute subdural hematoma can cause more widespread brain damage due to its diffuse nature and associated underlying injury. Prognosis depends on bleed size and location, diagnosis speed, patient health, and prompt medical intervention. Neither is inherently “better” nor “worse”; both are severe brain injuries requiring urgent medical management.
When to Seek Medical Attention
Recognizing when to seek medical attention after a head injury is important due to the potential for brain hematomas. Any head trauma warrants careful observation. Seek immediate medical evaluation if symptoms occur, such as:
Loss of consciousness
Confusion
Persistent or worsening headache
Repeated vomiting
Slurred speech
Weakness or numbness on one side of the body
Changes in pupil size
Even minor head injuries can lead to serious hematomas, especially chronic subdural hematomas, where symptoms may not appear for days or weeks. Early diagnosis and timely intervention improve outcomes for both epidural and subdural hematomas.