Had lp 2 weeks ago, pressure/pain in lower back, burning sensation in legs sometimes. while playing badminton got light headed and have a sore neck.

Drink more fluids: it is important to drink plenty of fluids after an LP. dehydration will cause lightheadedness and headache.

Lumbar puncture: Up to 25 percent of people who have undergone a lumbar puncture develop a headache afterward due to a leak of fluid into nearby tissues. You may feel pain or tenderness in your lower back after the procedure. The pain might radiate down the back of your legs.