Sacroiliitis (Inflamed Sacroiliac Joint): Symptoms and Treatment

What is sacroiliitis?

Sacroiliitis is inflammation of one or both sacroiliac joints, the joints that connect the base of the spine (the sacrum) to the pelvic bones. Although it moves very little, this joint transfers the weight of the trunk to the legs with every step, so any irritation there — also described as an "inflamed sacroiliac joint" or "sacroiliac joint dysfunction" — can cause noticeable pain in the lower back and buttocks.

You'll sometimes see the condition misspelled as "sacroilitis" or "sacroleitis" online: both refer to the same thing.

Symptoms of sacroiliitis

The main symptom is pain over the sacrum or just below the waistline, on one side or both, that can radiate to the buttock, hip, or back of the thigh, though it rarely travels past the knee. Other common signs:

Stiffness on getting up in the morning that eases after a while of moving around.
Pain that worsens with prolonged standing, climbing stairs, standing up from a chair, or twisting the trunk.
Discomfort when shifting weight from one leg to the other, or with the first step after sitting.
A feeling of pelvic instability, especially during pregnancy.

Bilateral vs. unilateral sacroiliitis: what each one suggests

Whether the pain affects one joint (unilateral) or both (bilateral) is a clue to the underlying cause, though it isn't a diagnosis on its own. Unilateral sacroiliitis tends to be linked to mechanical overload, a direct blow, or a leg-length difference. Bilateral, symmetric involvement shows up more often in inflammatory conditions such as ankylosing spondylitis, which affects both sides in the large majority of diagnosed cases. A clinician can get a first read on this from the physical exam, though imaging is what confirms the underlying cause.

Common causes

Mechanical overload: repetitive strain, sustained poor posture, or a sudden change in physical activity.
Pregnancy: hormonal changes loosen the pelvic ligaments to prepare for delivery, which can destabilize the joint.
A fall or direct impact to the area.
Leg-length differences, which alter pelvic mechanics while walking.
Inflammatory conditions, such as ankylosing spondylitis, psoriatic arthritis, or inflammatory bowel disease.
Joint infection, rare but one that needs urgent medical attention.

Is sacroiliitis serious?

In most cases, no. Mechanical sacroiliitis — by far the most common type — usually responds well to conservative care and doesn't leave lasting damage. That said, a few signs are worth checking with a doctor promptly:

Fever or feeling generally unwell along with the pain, which can point to an infection.
Pain that starts after a significant fall or direct-impact injury.
Tingling, leg weakness, or trouble controlling the bladder or bowel.
Pain that doesn't improve over several days or keeps getting worse.

Outside of those cases, leaving sacroiliitis unaddressed can still prolong the pain and limit mobility over time, as the Cleveland Clinic notes, so it's worth acting on it rather than waiting for it to settle on its own.

Diagnosis

A physical exam — pressing on and moving the pelvis through different positions to reproduce the pain — is usually enough to point to a mechanical cause. If an inflammatory or infectious cause is suspected, or if the pain doesn't improve with initial care, the next step is imaging (X-ray or MRI) and, occasionally, blood work.

Treating sacroiliitis

Conservative care is the first line when the cause is mechanical:

Staying active within your pain limits — prolonged rest tends to make the stiffness worse.
Physical therapy and stabilization exercises for the pelvis and core.
Anti-inflammatory medication, prescribed by a doctor when the pain calls for it.
Chiropractic adjustment of the pelvis for mechanical cases.

When the cause is inflammatory — ankylosing spondylitis, for example — treatment is led by rheumatology and may include specific medication; chiropractic care and physical therapy can support that treatment, but they don't replace it.

How chiropractic care can help

A chiropractic examination helps identify whether the joint is restricted or overly mobile, so care can be tailored to each case. Specific pelvic adjustments, combined with stabilization exercises, typically bring gradual relief and help prevent flare-ups in mechanical cases. If the pain feels more like sciatica running down the whole leg, or if you're also noticing hip and leg pain, it's worth mentioning at your visit — it helps pin down the actual source. For pregnant patients, adjustments are tailored specifically to each trimester.

Is it good to walk with sacroiliitis?

Yes — walking at a comfortable pace is usually better than complete rest, since it keeps the joint moving without the impact load of running or jumping. The sensible approach is to adjust distance and pace to what your pain allows, stop if you get clear discomfort, and avoid uneven ground or carrying heavy loads during a flare-up.

Can you work with sacroiliitis?

In most cases, yes, with a few adjustments: change position every 30-40 minutes if your job involves sitting or standing still, avoid carrying loads asymmetrically, and use a chair with good lower-back support. If your job involves heavy physical effort, repeated bending, or heavy lifting, you may need temporary changes to your tasks while the acute episode resolves.

Prevention

Strengthening the core and glute muscles, keeping a balanced posture whether standing or sitting, avoiding always carrying weight on the same side, and warming up before physical activity all lower the odds that mechanical sacroiliitis comes back.

Frequently asked questions

How is sacroiliac pain different from sciatica? Sacroiliac pain tends to stay more localized in the lower back and buttock, while sciatica more often radiates down the whole leg, sometimes as far as the foot.

Should I rest completely? No. Prolonged rest can actually increase stiffness; it's better to stay moving within your pain limits.

Is sacroiliitis serious? Generally not. Most cases are mechanical and improve with conservative care. It only needs urgent attention if there's fever, a significant prior injury, or tingling and leg weakness.

Is bilateral sacroiliitis worse than unilateral? Not necessarily worse, but it is different: when both sides are affected equally, it's worth ruling out an inflammatory cause with a doctor, while one-sided pain tends to point to a mechanical cause.

Is it good to walk with sacroiliitis? Yes — walking within what your pain allows beats complete rest; avoid the impact of running or jumping during a flare-up.

Can you work with sacroiliitis? Yes in most cases, by adjusting your posture, changing position often, and avoiding asymmetric loads. Physically demanding jobs may need temporary adjustments.

How long does sacroiliitis take to improve? The mechanical kind usually improves within a few weeks with appropriate care. If it's inflammatory, the timeline depends on treating the underlying condition and can be longer.

When should I see a professional? If the pain is severe, doesn't improve over several days, comes with fever, or presents with tingling or leg weakness.