Piriformis syndrome usually starts with pain, tingling, or numbness in the buttocks. Pain can be severe and extend down the length of the sciatic nerve (called sciatica). The pain is due to the piriformis muscle compressing the sciatic nerve, such as while sitting on a car seat or running. Pain may also be triggered while climbing stairs, applying firm pressure directly over the piriformis muscle, or sitting for long periods of time.
http://www.webmd.com/pain-management/guide/piriformis-syndrome-causes-symptoms-treatments
Sciatica usually affects only one side of the lower body. Often, the pain extends from the lower back all the way through the back of the thigh and down through the leg. Depending on where the sciatic nerve is affected, the pain may also extend to the foot or toes.
http://www.webmd.com/back-pain/guide/sciatica-symptoms
Cause: Piriformis syndrome. The piriformis is a muscle found deep inside the buttocks. It connects the lower spine to the upper thighbone and runs directly over the sciatic nerve. If this muscle goes into spasm, it can put pressure on the sciatic nerve, triggering symptoms of sciatica.
http://www.webmd.boots.com/back-pain/ss/slideshow-visual-guide-to-sciatica
Sciatica is caused by irritation of the root(s) of the lower lumbar and lumbosacral spine. Additional common causes of sciatica include: 1  Lumbar spinal stenosis (narrowing of the spinal canal in the lower back)  Degenerative disc disease (breakdown of discs, which act as cushions between the vertebrae)
http://www.webmd.com/back-pain/guide/sciatica-symptoms
Sciatica is caused by irritation of the root(s) of the lower lumbar and lumbosacral spine. Additional common causes of sciatica include: Lumbar spinal stenosis (narrowing of the spinal canal in the lower back)
http://www.webmd.com/back-pain/guide/sciatica-symptoms
Sciatica refers to back pain caused by a problem with the sciatic nerve. This is a large nerve that runs from the lower back down the back of each leg. When something injures or puts pressure on the sciatic nerve, it can cause pain in the lower back that spreads to the hip, buttocks and leg. For most people, the sciatica pain goes away naturally.
http://www.webmd.boots.com/back-pain/ss/slideshow-visual-guide-to-sciatica
The sciatic nerve is a thick and long nerve in the body. It passes alongside or goes through the piriformis muscle, goes down the back of the leg, and eventually branches off into smaller nerves that end in the feet. Nerve compression can be caused by spasm of the piriformis muscle.
http://www.webmd.com/pain-management/guide/piriformis-syndrome-causes-symptoms-treatments
Piriformis syndrome is an uncommon neuromuscular disorder that is caused when the piriformis muscle compresses the sciatic nerve. The piriformis muscle is a flat, band-like muscle located in the buttocks near the top of the hip joint.
http://www.webmd.com/pain-management/guide/piriformis-syndrome-causes-symptoms-treatments
Additional common causes of sciatica include: 1  Lumbar spinal stenosis (narrowing of the spinal canal in the lower back) 2  Degenerative disc disease (breakdown of discs, which act as cushions between the vertebrae)  Spondylolisthesis (a condition in which one vertebra slips forward over another one)
http://www.webmd.com/back-pain/guide/sciatica-symptoms
Sciatica is a common type of pain affecting the sciatic nerve, a large nerve extending from the lower back down the back of each leg. Common symptoms of sciatica include: 1  Lower back pain. 2  Pain in the rear or leg that is worse when sitting. 3  Hip pain.  Burning or tingling down the leg.
http://www.webmd.com/back-pain/guide/sciatica-symptoms
what causes piriformis sciatica
Piriformis sciatica is caused by irritation of the root of the lower lumbar and lumbosacral spine.