The piriformis muscle often gets a lot of press because it can be the culprit behind symptoms of pain. Many people have heard the phrase piriformis syndrome and possibly also heard it lumped together with the term sciatica. But what is piriformis syndrome? And, is it the same thing as sciatica?

Defining piriformis syndrome

Piriformis syndrome is a neuromuscular condition that occurs when some part of the piriformis muscle puts pressure on the sciatic nerve (a major nerve that runs from the lumbar spine down the back of the legs) and causes pain.

What’s the difference between piriformis syndrome and sciatica?

In both piriformis syndrome and sciatica, pain is felt because something is pressing on the sciatic nerve. Generally, you can distinguish between these two conditions based on the source of what’s creating the pressure on the sciatic nerve. In the case of sciatica, what’s pressing on the sciatic nerve is located in the spine. It’s often bone, specifically one or more vertebrae in the back, but it could also be a vertebral disc itself that is pressing on the sciatic nerve, due to a disc herniation or other spinal issue. 

In the case of piriformis syndrome, what’s pressing on the sciatic nerve is muscle, specifically, the piriformis muscle. It’s important to distinguish between the two because even though the pain may feel very similar, the treatment is different. If you think you may be experiencing either piriformis syndrome or sciatica, see your doctor. Therapies range depending on the specific situation and can vary from surgery to appropriate stretching of piriformis to physical therapy.

What causes piriformis syndrome?

Piriformis syndrome can have several different causes. They are sometimes grouped into primary and secondary types. Primary causes are those related to an unusual location of the sciatic nerve with respect to the location of the piriformis muscle, for example, when part or all of the sciatic nerve runs through the piriformis muscle, rather than inferior to it, which is the more common path. Secondary causes are those that occur as a result of activities that may overuse the muscle (like running), as a result of accidents, or as a result of a habit that compresses the nerve, such as prolonged sitting in a car or sitting on your wallet when it is in your back pocket.

What are the symptoms of piriformis syndrome?

Because there is considerable variation in the causes of piriformis syndrome, there is also a lot of variability in the specific locations and situations that cause pain. Some of the most common symptoms of piriformis syndrome include pain in one or both buttocks and possibly down the back of the leg. Pain when sitting for a long time is also very common.

A quick way to gain more information about the likely cause of pressure on the sciatic nerve is this:

1. Lie on your back with both legs straight on the floor.
2. Now, lift one leg up while keeping it straight.
3. Can you lift your leg more than a few inches off the floor before you feel any pain?

If you answered yes, then the culprit is more likely to be muscular. But if even a small lift of the leg produces pain, then the culprit is more likely to be bone. Either way, if you are experiencing frequent or constant pain, you should see your doctor to rule out causes of sciatica, such as a herniated disc or a vertebra pressing on the sciatic nerve, and to find a course of treatment that is appropriate for you.

Further reading

If you want to learn more about what the piriformis muscle is and what it does, check out the other articles in our series on the piriformis muscle: The Piriformis Muscle.