Sacrum pain can be caused by sitting a long time, sacroiliac joint problems, injury, or pregnancy. See a doctor if it persists.
Common causes
- Sitting for long periods.
- Sacroiliac (SI) joint dysfunction.
- Injury or fall.
- Pregnancy and childbirth.
- Arthritis.
- Sciatica.
- Fracture (osteoporosis).
Home care
Heat or ice, a cushion and stretching.
See a doctor
If pain follows injury, lasts weeks, or with numbness.
Emergency
Loss of bladder or bowel control.
Anatomy
The sacrum is a triangular bone at the base of the spine, joined to the pelvis at the sacroiliac (SI) joints. It supports the upper body’s weight. Sacral pain is felt in the lower back and buttocks. SI joint dysfunction accounts for about 15 to 25 percent of low back pain in some estimates.
- Pregnancy and childbirth loosen ligaments and stress the SI joint.
- A fall onto the tailbone can bruise or fracture the sacrum.
- Ankylosing spondylitis and other inflammatory arthritis cause SI joint inflammation, with morning stiffness that improves with movement.
- Pressure sores form over the sacrum in people who are bedridden.
Care
Heat or ice, NSAIDs, gentle stretching and core strengthening help. Use cushions when sitting. See a doctor for severe pain after injury, numbness in the groin or leg, bowel or bladder changes, fever or pain that wakes you at night. Imaging and injections are options for persistent SI pain, and physical therapy is the first line.
Anatomy
The sacrum is a triangular bone at the base of the spine formed by five fused vertebrae, joining the pelvis at the sacroiliac joints. Pain may come from sacroiliac joint dysfunction, pregnancy, injury, arthritis or ankylosing spondylitis.
Care
Heat, gentle stretching, physical therapy and anti inflammatory medicines help. See a doctor for pain after falls, with fever or with bowel or bladder changes.
Sacroiliac joint and causes
The sacrum anchors the pelvis through the sacroiliac joints, which move only a few millimeters. SI joint dysfunction accounts for 15 to 30 percent of chronic low back pain by some estimates. Pregnancy relaxin loosens ligaments. Ankylosing spondylitis (inflammatory arthritis) begins with sacroiliitis in young adults, causing morning stiffness longer than 30 minutes.
Treatment
Physical therapy to stabilize the pelvis, SI belts, NSAIDs and injections guide treatment. Pain after a fall may be a sacral stress fracture, mainly in older women and athletes. Red flags include numbness in the saddle area and loss of bowel or bladder control (cauda equina), which is an emergency.
Based on data from the Mayo Clinic and the American Academy of Orthopaedic Surgeons
