Step 1: Post dural puncture headache (PDPH), also called post spinal headache, is caused by leakage of CSF through the dural puncture, which lowers intracranial pressure and produces traction on the meninges and supporting structures.
Step 2: It is positional - it worsens on sitting or standing upright and is relieved by lying down. Onset is usually 12 to 72 hours after the procedure. In most cases it lasts about 7 to 10 days, so 10 days is the best fit among the options.
Step 3: Risk factors include young age, female sex, pregnancy, large bore needle and multiple punctures. Conservative treatment includes bed rest, fluids, analgesics, caffeine and sumatriptan; if it fails, an epidural blood patch is given. The shorter options (10 min, 1 hr, 1 week) are too brief for the typical self-limiting course, hence 10 days is correct.