Piriformis syndrome occurs when the piriformis muscle, located in the buttock, becomes tight or spasms, irritating the nearby sciatic nerve. This can lead to symptoms such as buttock pain, tingling, or numbness that may radiate down the leg. The condition is often aggravated by prolonged sitting, certain activities, or muscle imbalances. Treatment generally includes stretching exercises, physical therapy, and sometimes medications or injections to relieve pain and improve muscle function.