The first step is hydrating to build cerebral spinal fluid pressure. Sometimes that's by IV (fluids through a tube and needle into a vein), or your doctor may tell you to drink something with a lot of caffeine. You may be on strict bed rest for 24-48 hours.
If that doesn't work, your doctor may prescribe gabapentin, hydrocortisone, or theophylline.
Your anesthesiologist might create a blood patch, injecting your own blood into the space to clot and seal the leak.