Synopsis
Recognise cerebrospinal-fluid volume loss, distinguish post-dural-puncture headache from spontaneous intracranial hypotension, and arrange safe imaging and definitive leak-directed care without relying on opening pressure alone.
- Low-pressure headache usually reflects loss of cerebrospinal-fluid volume through a dural leak or a cerebrospinal-fluid venous fistula; measured lumbar opening pressure is often normal.
- The classic symptom is headache that develops or worsens after becoming upright and improves after lying flat, but the delay and recovery time vary and chronic cases can lose obvious orthostatic behaviour.
- Ask about recent lumbar puncture, spinal or epidural anaesthesia, spinal surgery, vigorous stretching or minor trauma, and features suggesting an underlying connective-tissue disorder.
Key red flags
New focal deficit, seizure, somnolence or a changing non-postural headache may reflect subdural haematoma, venous thrombosis or marked brain sag and needs urgent neuroimaging.
Investigation priorities
Define the postural timing, precipitant and possible complication.
Management branches
A new headache has a convincing upright-worse pattern or follows dural puncture.
- Record onset, postural latency, procedure and medicines, then assess observations, mental state, focal neurology, meningism and features of raised intracranial pressure or infection.
- Send thunderclap headache, seizure, reduced consciousness, new deficit, fever or severe progressive symptoms through urgent same-day imaging and specialty assessment.
Key medicines
ParacetamolUse the usual adult oral dose according to the BNF, reducing or avoiding it where low body weight, liver disease or excess alcohol changes the safe maximum.
CaffeineOral caffeine is sometimes used for brief symptomatic relief at a locally agreed dose; intravenous regimens require anaesthetic or specialist prescribing and monitoring.