Mayo Clinic | American Hospital

Sacroiliitis (say-kroe-il-e-I-tis) is a painful condition of swelling and irritation, called inflammation, that affects one or both sacroiliac joints. These joints sit where the lower spine and pelvis meet.

Sacroiliitis can cause pain and stiffness in the buttocks or lower back. The pain might go down one or both thighs. Standing or sitting for a long time or climbing stairs can make the pain worse.

Sacroiliitis can be hard to diagnose because it can be like other causes of low back pain. It's been linked to a group of diseases that cause inflammatory arthritis of the spine. Treatment might involve physical therapy and medicines.

Symptoms

The pain of sacroiliitis most often happens in the buttocks and lower back. It also can affect the legs, groin and even the feet. The pain may get better with certain movements.

The following can make sacroiliitis pain worse:

Sitting, walking or standing for a long time.
Running.
Stair climbing.
Sleeping on the side with the pain.

Causes

Causes of sacroiliac joint issues include:

Injury. A sudden hit to the sacroiliac joints, such as from a motor vehicle accident or a fall, can damage them.
Arthritis. Wear-and-tear arthritis, also known as osteoarthritis, can happen in sacroiliac joints. So can a type of arthritis that affects the spine, called ankylosing spondylitis.
Pregnancy. The sacroiliac joints loosen and stretch for childbirth. The added weight and changed way of walking during pregnancy can stress these joints.
Not moving enough. A lack of exercise can lead to tight muscles and tension around the joint.
Infection. Rarely, a sacroiliac joint can become infected. The risk is higher in people who have diabetes or who shoot street drugs with a needle.
Surgery to fuse the spine. This can cause damage to the joint, ligaments and nerves around the joint.

Risk factors

Certain conditions may raise the risk of swelling and irritation, called inflammation, in the sacroiliac joints.

Inflammatory forms of arthritis, such as ankylosing spondylitis and psoriatic arthritis, may increase the risk of sacroiliitis. Inflammatory bowel disease, including Crohn's disease and ulcerative colitis, also may increase the risk.

Changes that happen to the body during pregnancy and childbirth also can stress the sacroiliac joints and cause pain and swelling.

Complications

Sacroiliitis can make it hard to do certain actions, such as bending, lifting, staying in one place and rising from being seated. The lasting pain of sacroiliitis can lead to depression and loss of sleep.

Diagnosis

During the physical exam, a healthcare professional may try to find the pain by pressing on the hips and buttocks while you lie in certain ways. These are called provocation tests. The healthcare professional also checks how the condition affects the way you walk.

Imaging tests

An X-ray of the pelvis can show damage to the sacroiliac joint. An MRI can show whether the damage is the result of ankylosing spondylitis.

Numbing shots

If putting numbing medicine into the sacroiliac joint eases the pain, it's likely that the issue is in the sacroiliac joint.

Treatment depends on symptoms and the cause of the sacroiliitis. Doing exercises that stretch and build strength and taking nonsteroidal anti-inflammatory pain relievers you can get without a prescription are often the first treatments.

Medicines

Depending on the cause of the pain, these might include:

Pain relievers. Nonsteroidal anti-inflammatory pain relievers you can get without a prescription include ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve). You also can try acetaminophen (Tylenol). If these don't give enough relief, a healthcare professional might prescribe a stronger pain reliever.

Pain relievers you put on the skin over the sore area may give some relief. These may include lidocaine or menthol patches.
Muscle relaxers. Medicines such as cyclobenzaprine (Amrix, Tonmya) might help ease the muscle spasms that often go along with sacroiliitis.
Biologics. Biologic medicines treat many conditions in which the immune system attacks healthy tissues by mistake, called autoimmune conditions. Interleukin-17 (IL-17) inhibitors include secukinumab (Cosentyx) and ixekizumab (Taltz). Tumor necrosis factor (TNF) inhibitors include etanercept (Enbrel), adalimumab (Humira), infliximab (Remicade) and golimumab (Simponi). Both IL-17 inhibitors and TNF inhibitors may relieve sacroiliitis.
Disease-modifying antirheumatic drugs (DMARDs). DMARDs are medicines that lessen swelling and irritation, called inflammation, and pain. Some DMARDs target and block an enzyme called Janus kinase (JAK). JAK inhibitors include tofacitinib (Xeljanz) and upadacitinib (Rinvoq).

Therapy

A healthcare professional, such as a physical therapist, can teach range-of-motion and stretching exercises. You do these exercises to ease pain and help the low back and hips move better. Exercises for strength help protect the joints and make posture better.

A physical therapist may suggest using a support, such as a pelvic belt, to help limit motion and ease pain.

Surgical and other procedures

If other methods don't relieve pain, a healthcare professional might suggest:

Shots into the joint. Corticosteroids that go into the joint may ease swelling and pain. An image-guided shot into the joint may help if other treatments haven't worked. X-ray or ultrasound may help guide the shot to the right place. You can get only a few of these shots a year because the steroids can weaken nearby bones and tendons.
Radiofrequency denervation. Radiofrequency energy can damage or destroy the nerve causing the pain.
Platelet-rich plasma. This treatment involves injecting some of your own blood into the joint. The part of the blood used for the treatment has more platelets than usual. Platelets are cells in blood that help it clot and repair tissue damage.

Some studies show that this treatment eases sacroiliitis pain. More study is needed.
Joint fusion. Surgery is a rare treatment for sacroiliitis. It involves joining the two bones with metal hardware to ease sacroiliitis pain.

Lifestyle and home remedies

Home treatments for sacroiliitis pain include:

Pain relievers you get without a prescription. Medicines such as ibuprofen (Advil, Motrin IB, others) and acetaminophen (Tylenol, others) may help relieve the pain of sacroiliitis. Some of these medicines can cause stomach upset or kidney or liver issues.
Rest. Changing activities that make pain worse or not doing them for a time may help. Good posture also helps.
Ice and heat. Switching between ice and heat might help ease sacroiliac pain.

Preparing for an appointment

You might start by seeing your main healthcare professional, who may send you to a specialist in diseases that involve the bones and joints, known as a rheumatologist. You also might see an orthopedic surgeon.

What you can do

Take a family member or friend along, if possible. Someone who's with you can help you remember the information you get.

Make a list of:

Your symptoms and when they began.
Key information, including recent life changes and whether any first-degree relatives, such as a parent or a sibling, have had symptoms like yours.
All medicines, vitamins and other supplements you take, including dosages.
Questions to ask your healthcare professional.

For sacroiliitis, questions to ask include:

What's likely causing my symptoms?
What are other possible causes?
What tests do I need?
Is my condition likely to go away or to last?
What's a good treatment for me?
How can I manage this condition with my other health conditions?
Are there restrictions I need to follow?
Are there brochures or other printed materials I can have? What websites do you suggest?

Ask all the questions you have.