Subdural hematoma (SDH) is bleeding between the dura and the arachnoid. Symptoms depend on how fast blood accumulates, the size of the clot, and the patient’s age or brain atrophy. They may appear within minutes (acute), days (sub-acute) or weeks (chronic).
- Headache
Persistent, often severe and worsening; classically more noticeable on awakening. - Nausea and vomiting
Raised intracranial pressure triggers frequent vomiting with little relief. - Altered consciousness
Drowsiness, lethargy, sudden confusion, or memory loss; a lucid interval may precede deterioration. - Focal neurology
Weakness or numbness on the side opposite the bleed, slurred speech, unequal pupils, or vision changes. - Seizures
Focal or generalised fits are common when the cortex is irritated. - Balance & gait disturbance
Dizziness, unsteadiness or difficulty walking, especially in chronic SDH of older adults. - Behaviour / personality change
Apathy, irritability or disorientation may be the only clue in slowly evolving cases. - Coma & brain-stem signs
If mass effect progresses, pupils dilate, breathing becomes irregular, and the patient loses consciousness.
Infants present with a rapidly enlarging head circumference, tense fontanelle and irritability. Any neurological symptom after even minor head trauma warrants urgent CT imaging.
| Symptom | Acute SDH | Chronic SDH |
|---|---|---|
| Onset | Minutes–hours | Weeks |
| Headache | Sudden, severe | Mild, waxing |
| Consciousness | Rapid drop | Fluctuating confusion |
| Vomiting | Early, forceful | Intermittent |
| Weakness | Immediate hemiparesis | Gradual gait drift |
| Seizure | Common | Possible |
| Coma | May develop quickly | Late if untreated |