You may have heard of sciatica, a pain that starts in the buttocks and runs down one or both legs. Sciatica is usually caused by pressure or irritation of nerves in the lower back. One condition that causes pressure on those nerves is called piriformis syndrome.

The piriformis is a muscle that extends from the front of the sacrum. That’s the triangle-shaped bone between your two hipbones in your pelvis. The muscle extends across the sciatic nerve to the top of the femur. The femur is the large bone in your upper leg.

The piriformis helps the thigh move side to side. A piriformis muscle spasm can put pressure on the sciatic nerve and cause symptoms. The result is piriformis syndrome.

Sciatica is the main symptom of piriformis syndrome. You may experience others, however. Often the discomfort is felt in another part of the body, such as the back of the leg. This is known as referred pain.

Some other common signs of piriformis syndrome include:

  • numbness and tingling in the buttocks that may extend down the back of the leg
  • tenderness of the muscles in the buttocks
  • difficulty sitting comfortably
  • pain while sitting that gets worse the longer you sit
  • pain in the buttocks and legs that worsens with activity

In serious cases of piriformis syndrome, the pain in your buttocks and legs can be so severe it becomes disabling. You may become unable to complete basic, everyday tasks, such as sitting at a computer, driving for any length of time, or performing household chores.

The piriformis gets a workout every day. You use it when you walk or turn your lower body. You even use it just from shifting your weight from one side to the other. The muscle can become injured or irritated from long periods of inactivity or too much exercise.

Some common causes of piriformis syndrome include:

  • overuse from excessive exercise
  • running and other repetitive activities involving the legs
  • sitting for extended periods
  • lifting heavy objects
  • extensive stair climbing

Injuries can also damage the muscle and cause it to press down on the sciatic nerve. Typical piriformis injury causes include:

  • a sudden twist of the hip
  • a bad fall
  • a direct hit during sports
  • a vehicle accident
  • a penetration wound that reaches the muscle

Anyone who sits for long periods of time, such as people who sit at a desk all day or in front of a television for extended periods of time, are at a higher risk for piriformis syndrome. You’re also at increased risk if you participate in frequent, rigorous lower-body workouts.

See your doctor if you experience pain or numbness in your buttocks or legs that lasts more than a few weeks. Sciatica can linger for several weeks or longer, depending on the cause. You should also see your doctor if your symptoms come and go frequently.

Your doctor appointment will include a review of your medical history, your symptoms, and any possible causes of your pain. Be prepared to discuss your symptoms in detail. If you had a recent fall or recall straining a muscle during sports, be sure to share that information with your doctor. It doesn’t matter if you’re unsure that’s what triggered your symptoms.

Your doctor will also do a physical exam. You will be put through a range of movements in order to tell what positions cause pain.

Some imaging tests may also be necessary to help rule out other causes of your pain. An MRI scan or a CT scan may help your doctor determine whether arthritis or a ruptured disk is causing your pain. If it appears that piriformis syndrome is causing your symptoms, an ultrasound of the muscle may be helpful in diagnosing the condition.

Piriformis syndrome often doesn’t need any treatment. Rest and avoiding activities that trigger your symptoms are usually the first approaches to take.

You may feel better if you alternate ice and heat on your buttocks or legs. Wrap an ice pack in a thin towel so you don’t have the ice pack directly touching your skin. Keep the ice on for 15 to 20 minutes. Then use a heating pad on a low setting for about the same time. Try that every few hours to help relieve the pain.

Over-the-counter painkillers, such as ibuprofen (Advil) or naproxen (Aleve), may also help you feel better.

The pain and numbness associated with piriformis syndrome may go away without any further treatment. If it doesn’t, you may benefit from physical therapy. You’ll learn various stretches and exercises to improve the strength and flexibility of the piriformis.

One simple exercise you can try is to lie flat on your back with both knees bent. Lift your left ankle up and rest it against your right knee. Then gently pull your right knee toward your chest and hold it for five seconds. Slowly return both legs to their starting positions and do the same stretch on the other side. Then repeat both stretches.

In serious cases of piriformis syndrome, you may need injections of corticosteroids to help relieve inflammation of the muscle. You may also find relief after transcutaneous electrical nerve stimulator (TENS) treatment. A TENS device is a handheld unit that sends small electrical charges through the skin to the nerves underneath. The electrical energy stimulates the nerves and interferes with pain signals to the brain.

If you still need relief, you may need surgery to cut the piriformis muscle to ease pressure on the sciatic nerve. However, this is rarely needed.

Even though exercise can sometimes cause piriformis syndrome, regular exercise can help reduce your risk. Muscles need exercise to stay strong and healthy. To help prevent injuries that lead to piriformis syndrome, you should do the following:

  • warm up and stretch before you run or engage in a vigorous workout
  • gradually build up the intensity of whatever exercise or sport you’re doing
  • avoid running up and down hills, or over uneven surfaces
  • get up and move around so you’re not sitting or lying down too long without some activity

If you have already been treated for piriformis syndrome, you may be at a slightly higher risk of it returning. If you follow through on the exercises learned in physical therapy, you should be able to avoid a relapse barring a serious injury.

Piriformis syndrome is an uncommon condition and can be difficult to diagnose. It can usually be treated with some rest and physical therapy.

Staying active, but making sure you stretch before exercising, should help keep your backside and legs feeling better before, during, and after your workout.