What are the side effects of a lumbar puncture?

Headache, bleeding: The most common side effect of a lumbar puncture is headache due to the drop in cerebrospinal fluid pressure. This normally resolves in a few days with fluids and rest, but sometimes requires a second procedure called a blood patch before it resolves. Lp can also cause bleeding and infection, although these are much more rare.

Head ache ,infection: Spinal headache can be severe requiring bed rest and sometimes a blood clot patch over puncture site and infection is potentially very rare but also dangerous.