Pain in the Left Buttock: Causes and Relief

By Your Health Magazine Health Information Team

Pain in the left side of the bottom is often caused by a strained buttock muscle, irritation of the sciatic nerve, pressure on tissues from prolonged sitting, or a problem involving the lower back, hip, or sacroiliac joint. The location and character of the pain—aching, burning, shooting, tender, or accompanied by numbness—can help narrow the possibilities. Mild pain after activity may improve with conservative care, but weakness, bowel or bladder changes, fever, or pain after a serious injury requires prompt medical attention.

Common Causes of Left Buttock Pain

Possible cause	Typical clues
Muscle strain or tendon irritation	A localized ache or tenderness after exercise, lifting, climbing, running, slipping, or an unfamiliar activity. Contracting or stretching the muscle may hurt.
Sciatica	Burning, electric, or shooting pain that may begin in the lower back or buttock and travel down the back of the leg. Tingling, numbness, or weakness may occur.
Piriformis or deep gluteal irritation	Deep buttock pain that is often aggravated by prolonged sitting, driving, running, stairs, or pressure on the affected side.
Sacroiliac joint pain	Pain near the dimple at the lower back and upper buttock, sometimes extending into the thigh. Standing on one leg, stairs, prolonged sitting, or getting out of a chair may aggravate it.
Hip-related pain	Buttock pain accompanied by groin or outer-hip pain, stiffness, limited hip movement, limping, or discomfort when lying on the affected side.
Direct pressure or injury	Tenderness after a fall, bruise, injection, or extended sitting on a hard surface.

Is It Sciatica?

Sciatica is not simply any pain in the buttock. It occurs when a problem affects the sciatic nerve or the nerve roots that form it. According to MedlinePlus information about sciatica, symptoms can include pain, weakness, numbness, or tingling that starts in the lower back and extends through one side of the buttock and leg.

Sciatic pain is often described as burning, stabbing, or shock-like rather than as a single tender spot. Coughing, sneezing, bending, or prolonged sitting may make it worse. A herniated spinal disk and narrowing around the nerves are possible causes, although the exact source is not always identified.

Piriformis or deep gluteal irritation can produce similar symptoms when the sciatic nerve is irritated within the buttock. Because symptoms overlap, it is difficult to determine the source based only on where it hurts.

Could the Sacroiliac Joint Be Responsible?

The sacroiliac joints connect the lower spine to the pelvis. Irritation on the left side can cause pain in the left buttock and lower back, with possible discomfort in the thigh or groin. Sacroiliitis symptoms and causes include buttock or lower-back stiffness and pain that may worsen with prolonged sitting or standing, running, climbing stairs, or sleeping on the painful side.

Injury, arthritis, pregnancy-related changes, inflammatory conditions, and, rarely, infection can affect this region. The tissues over the sacrum may also become uncomfortable from pressure or prolonged sitting. Understanding the role of the sacral fat pad in cushioning the lower back may help explain why discomfort near the top of the buttocks is not always caused by the hip or sciatic nerve.

What You Can Do for Mild Pain

If the pain is mild, began after activity, and is not accompanied by warning signs, the following measures may provide relief:

Reduce aggravating activity temporarily. Avoid heavy lifting, hill running, deep squats, or long periods of sitting if they increase the pain. Complete bed rest is generally not recommended.
Keep moving gently. Short walks and comfortable daily activities can prevent stiffness. Gradually increase activity as symptoms settle.
Use cold or heat carefully. A wrapped cold pack may help after a recent strain or bruise. Heat may relax tight muscles. Limit each application to about 15–20 minutes and protect the skin.
Change sitting positions. Sit evenly on both buttocks, avoid carrying a wallet in a back pocket, and take regular standing or walking breaks. A supportive cushion may reduce pressure from hard seating.
Try only comfortable movement. Gentle hip and back mobility may help, but stop if an exercise causes shooting pain, increasing numbness, or weakness.
Consider nonprescription pain relief cautiously. A pharmacist or healthcare professional can help determine whether an over-the-counter pain reliever is appropriate based on other medications, pregnancy, allergies, and kidney, liver, stomach, heart, or bleeding problems. Follow the product label.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases offers additional guidance on back-pain evaluation and treatment, including gradual activity, cold or heat, and physical therapy. More general information is available through the required MedlinePlus back pain resource.

How a Clinician Identifies the Cause

A primary care clinician, sports medicine physician, physiatrist, orthopedist, or physical therapist may evaluate persistent buttock pain. The assessment usually includes questions about recent activity or injury, the exact pain pattern, positions that aggravate it, and whether numbness or weakness is present.

The clinician may examine the lower back, hip, sacroiliac area, muscle strength, reflexes, sensation, and walking pattern. Imaging is not automatically needed for every new episode. X-rays, MRI, or other testing may be considered when symptoms persist, follow significant trauma, suggest a nerve problem, or raise concern about infection, fracture, inflammatory disease, or another underlying condition.

When to Seek Care

Seek emergency care for buttock or back pain accompanied by:

New loss of bladder or bowel control
Numbness around the genitals, inner thighs, or area that would contact a saddle
Rapidly worsening leg weakness or difficulty walking
Severe pain after a major fall, collision, or other trauma

Arrange prompt medical evaluation if the pain occurs with fever, redness, warmth, significant swelling, unexplained weight loss, a history of cancer, weakened immunity, or pain that is severe at night. Evaluation is also appropriate when pain travels below the knee, numbness or weakness develops, symptoms steadily worsen, or the pain does not begin improving after a few weeks.

Left buttock pain is usually musculoskeletal or nerve-related, but its precise source cannot be determined by location alone. Paying attention to radiation, numbness, weakness, tenderness, recent activity, and warning signs can help you decide whether conservative care or a professional evaluation is the appropriate next step.