B i.e. Occurs due to low CSF pressure Post Dural Puncture Headache (PDPH) Any breach of dura may result in PDPH. This may follow a lumber puncture, myelogram, spinal anesthesiaQ, wet epidural tapQ (in which epidural needle pierced dura) or uncomplicated epidural (dlt scratching of dura). It result from decreased intracranial pressure as CSF leaks from dural defect at a greater rate than it is being produced.Q The headache is BIL, frontal Or retro-orbital, occipital & extending into neck. It may be throbbing & associated with photophobia & nausea. The onset is usually 12-72 hoursQ following procedure (in first 3 days) may last for 1-2 weeksQ. The hallmark is its association with body positionQ (i.e. aggravated by sitting or standing & relieved by lying down)0 The incidence increases with ? 1. Larger needleQ 2. Cutting point (in comparision to pencil point) needle. 3. Young age, Female sex, PregnancyQ So, max incidence is expected in a wet epidural tap with a large epidural needle in an obstetric patient. Lowest incidence would be expected with an elderly male using 27 gauge pencil point needle. Management of PDPH Prevention by thinner needleQ (whitacre needle) Supine position, intravenous fluids & caffeine and analgesia. Epidural blood Patch is most effective treatment.