When the sacroiliac joints become inflamed or irritated, it can cause lower back pain and stiffness. This is known as sacroiliitis. In some cases, the pain may also radiate into the hips, buttocks, or legs.

The sacroiliac joints are in the lower back. They are responsible for connecting the sacrum — a large, triangular bone at the base of the spine — to each hip bone. They provide stability for the lower body and act as shock absorbers for the spine, absorbing much of the impact from walking and other activities.

The sacroiliac joints are involved in up to 30% of cases of lower back pain. Treatment for sacroiliac joint pain may include rest, ice, and over-the-counter (OTC) pain medication. In some cases, physical therapy or injections can help.

This article explores sacroiliac joint pain and what it feels like.

Lower body of a man with sacroiliac pain walking up stairs.Share on Pinterest
Photographer, Basak Gurbuz Derman/Getty Images

The two sacroiliac joints are in the lower back, where the sacrum and ilium meet on each side of the body. The sacrum is a large triangular bone above the tailbone. It connects to the ilium bones, which are at the back of the pelvis.

The bones of the sacroiliac joints connect with strong ligaments that stabilize the joint while allowing minimal movement. They have a protective, cushioning layer of cartilage lining them, and the spaces between them contain lubricating fluid.

People can experience sacroiliac joint pain differently. The symptoms may include:

  • dull aching pain across the sacral region
  • pain in both buttocks
  • pain that extends down the thigh to the knee
  • numbness and tingling in the legs
  • a stiff pelvis
  • pain that increases when standing up
  • legs that feel weak and unable to support the body
  • limping or taking shorter steps

Doctors may find it challenging to diagnose sacroiliac joint pain. They cannot easily examine the joints or test their motion, as they are deep inside the body. Therefore, they use a combination of physical exams, medical history, and imaging, such as X-rays or MRI scans, to diagnose the pain.

During the physical exam, a doctor may manipulate the joints by flexing and rotating the knee and hip to see if it causes pain.

However, because diagnosing the condition is challenging, people should not try to perform this test at home to self-diagnose. Instead, seek professional help.

Sacroiliac joint pain has a good prognosis. If it occurs in pregnancy, the symptoms usually resolve within 12 months after giving birth. In other cases, it may go away on its own or after treatment.

However, for some, the pain may persist or come and go.

Arthritis can cause sacroiliac joint pain. Inflammatory forms of arthritis, including ankylosing spondylitis and psoriatic arthritis, can inflame the sacroiliac joints and the lower vertebrae in the spine leading to pain and stiffness in the hips and lower back.

Osteoarthritis can also affect the sacroiliac joint. In this form of arthritis, the protective cartilage cushioning the ends of bones deteriorates, allowing the bones to rub against one another and causing pain.

Besides arthritis, the following things can contribute to sacroiliac joint pain:

  • Injury: If an individual falls or experiences a blunt impact, they can injure the sacroiliac joint.
  • Pregnancy: In preparation for childbirth, the body releases hormones that loosen the ligaments and joints in the pelvis. This changes how the sacroiliac joint moves and makes it less stable. The additional weight of pregnancy also stresses the sacroiliac joints, which can cause pain.
  • Walking pattern: If an individual has legs of differing lengths, or favors one leg because of pain or an old injury, the uneven load can stress the sacroiliac joint.
  • Spine surgeries: Surgery that fuses vertebrae in the lower spine affects the spine’s flexibility and can increase stress on the sacroiliac joint.
  • Infection: Although uncommon, the sacroiliac joint can become infected, which damages the tissue.

A doctor may recommend a combination of lifestyle changes, medications, and physical therapy to treat painful sacroiliac joints.

If these approaches do not relieve the pain, a doctor may suggest surgery to fuse the joints. However, this is a last resort that does not always have good outcomes.


The following medications may help relieve sacroiliac joint pain:

  • OTC or prescription pain medication
  • anti-inflammatory medications, such as nonsteroidal anti-inflammatory drugs
  • muscle relaxants

If an individual has sacroiliac joint pain secondary to inflammatory arthritis, their doctor may recommend biologics such as tumor necrosis factor inhibitors.

Physical therapy

A physical therapist can design a program of exercises and stretches to strengthen the muscles around the sacroiliac joint and help stabilize the joint. The therapist may also use hands-on techniques such as massage, manipulation, and mobilization to relieve pain.

If an individual has arthritis, their doctor may recommend water therapy which is gentle on the joints while still providing exercise and movement.

Nonsurgical procedures

If an individual still has sacroiliac joint pain following conservative treatments, their doctor may recommend cortisone injections directly into the joint. These shots effectively reduce pain and inflammation.

However, they usually require administration in a hospital setting under the guidance of medical imaging. Steroids can weaken bones and tendons, so a person can only have a few injections each year.

Another option is radiofrequency ablation. This involves using radio waves to destroy nerves that carry pain signals.

To manage the symptoms of sacroiliac joint pain, people can:

  • Avoid bed rest: Although some movements may be painful, doctors do not recommend total bed rest for this condition. Instead, people should aim to keep moving as much as they can, within safe limits. Modify or avoid activities that worsen the pain.
  • Try heat and cold therapy: Try alternating hot and cold compresses several times a day. The heat increases blood flow, while the cold reduces inflammation.
  • Change sleep position: People may find it helpful to sleep on their side with a pillow between the knees to support the hips and lower back.
  • Change posture: People should avoid crossing their legs while sitting, as this puts additional stress on the sacroiliac joints. Choose chairs with good lumbar support for the lower back.

Sacroiliac joint pain is a condition that causes pain in the lower back and hips. It may radiate down the legs to the knees and feel dull or numb.

Arthritis, pregnancy, injury, and spinal surgery can cause sacroiliac joint pain. A doctor may recommend medication, physical therapy, or nonsurgical procedures to treat the pain. Self-care measures include avoiding stressors, changing sleep positions, and applying hot and cold compresses.