Sacroiliac Joint Pain Causes and Treatment

Man with back pain trying to exercise
adamkaz/Getty Images

Sacroiliac joint pain (also referred to as SI joint pain or SI joint dysfunction) is among the common causes of low back pain. Typically, sacroiliac joint pain is very annoying and intrusive but it can most often be treated without drastic measures.


The sacrum, a triangle-shaped bone, sits just beneath the lumbar spine and above the tailbone (coccyx). The body's two sacroiliac joints are formed between the sacrum and the pelvic (iliac) bones to either side.

  • The sacroiliac joint is one of the large joints in the body and characteristically there is little motion involved with the sacroiliac joint.
  • The sacroiliac joint functions as a shock absorber, decreasing stress on the pelvis and spine.


Though sometimes the cause of sacroiliac joint pain remains unknown, there are a few known causes.

  • Pregnancy may cause temporary sacroiliac joint pain.
  • Uneven leg length that disrupts walking patterns.
  • An injury may cause sacroiliac joint pain.
  • The continued pounding pressure from an exercise like running may be a cause.

Since the sacroiliac joint is a synovial joint, it can be affected by arthritic conditions that result in cartilage damage or joint inflammation (e.g. ankylosing spondylitis).


Your doctor will consider your complete medical history, results from your physical examination and x-rays to determine the extent of joint damage and formulate a diagnosis. Your doctor may also find it valuable to obtain images from MRI, CT scan, and bone scan.


The primary symptom of sacroiliac joint pain, as its name suggests, is the pain.

  • The pain is usually in the lower back or back of the hip area.
  • It can also be painful in the groin and thigh area.
  • Pain is usually worse when standing and relieved by lying down.
  • In addition, when the sacroiliac joint is inflamed, there is usually stiffness that is worse in the morning and improves with activity.


The treatment regimen for sacroiliac joint pain includes:

  • Cortisone injections (up to three a year)
  • Oral NSAIDs (nonsteroidal anti-inflammatory drugs)
  • For some forms of SI joint inflammation (e.g., ankylosing spondylitis), anti-TNF drugs are indicated.
  • Physical therapy exercises can help flexibility and strength in the joint.
  • Wearing a sacroiliac belt to stabilize the joint.
  • Surgery, as a last resort, to fuse the sacroiliac joints.

It may be a combination of conservative treatments that work best for sacroiliac joint pain. Discuss all of your options with your doctor. Don't assume that nothing can be done to offer some relief.

Was this page helpful?