Why do you get back pain when sitting?

According to Spine-Health, back pain when sitting is a common symptom of sciatica, a condition in which the sciatic nerve that travels down the lower back and legs becomes irritated. Additional symptoms of sciatica include a tingling feeling down the leg, foot numbness and one-sided buttock pain.

Healthline explains that back pain that becomes worse after sitting may indicate a herniated disk, a condition in which one or more spinal disks push through the protective outer rings of the spine. Additional symptoms of a herniated disk include weak muscles, pins-and-needles sensations, pain on one side of the body and pain upon walking.