Can a brain hematoma occur without any symptoms?

Yes, a brain hematoma can occur—specifically in cases known as chronic subdural hematoma (cSDH)—without presenting any clear symptoms at the beginning. In fact, many of these hematomas are small in size when they first form and do not cause any immediate clinical discomfort to the patient, making their incidental discovery during imaging scans performed for other reasons quite common [4]. The nature of this condition depends on it being a slow-evolving process; a small amount of blood or fluid accumulates over time, giving the brain the opportunity to adapt to this mild pressure in the early stages.

Why does a brain hematoma remain silent?

Chronic subdural hematoma often arises as a result of a minor head injury, which the patient may not remember or associate with a serious event. Small blood vessels beneath the brain's membrane begin to leak slowly, and as the body fails to reabsorb this blood, a membrane forms around it and draws fluid inside, causing the hematoma to gradually increase in size [4]. Since the skull is a rigid structure, this expansion puts very slow pressure on brain tissue. Initially, the pressure is so slight that the patient does not feel functional changes, which explains why the condition remains "silent" for weeks or even months before symptoms begin to appear.

When do symptoms begin to appear?

Once the hematoma exceeds the brain's ability to adapt to the pressure, symptoms begin to appear gradually. The patient or those around them may notice unexplained weakness in a limb (arm or leg), facial drooping on one side of the body, or difficulty with speech [4]. Symptoms that appear as the hematoma grows also include chronic headaches that may worsen over time, feelings of confusion, episodes of dizziness, and imbalance when walking. It is important to understand that symptoms may not be constant; their severity can fluctuate over time.

Risk factors and medical follow-up

Specific groups are more susceptible to the development of these hematomas after minor head injuries, such as the elderly, those taking blood-thinning medications (such as warfarin or aspirin), or individuals with clotting disorders or liver disease [4]. In these patients, minor head bumps can lead to a slow bleed. If a small hematoma is discovered, doctors may choose a "conservative management" approach, which relies on careful monitoring and periodic follow-up with CT or MRI scans to ensure the hematoma is not growing [4]. To learn about the steps followed in more serious cases, you can view Emergency treatment procedures for brain hematoma (Arabic).

Emergency signs that must not be ignored

Although a hematoma can exist without symptoms, there are signs that require immediate medical intervention. If sudden seizures, loss of consciousness, sudden and severe muscle weakness, or a severe disturbance in consciousness occur, you must go to the emergency department immediately. Waiting may increase the risk of permanent neurological damage. It should also be noted that any head injury, no matter how minor it may seem in the elderly or those using blood thinners, requires careful medical evaluation to rule out a hidden bleed that may later develop into a hematoma [1], [4].

Medical references

• Cerebral Aneurysms
• Chronic subdural haematoma (cSDH) | CUH