Lower Back Pain: Causes and Relief

What lower back pain feels like

• A dull ache across the lower back, sometimes on one side
• Sharp pain or catching when bending, twisting or getting up
• Muscle spasm and stiffness, especially in the morning
• Pain spreading into the buttock or the back of the thigh
• Shooting pain down the leg past the knee, sometimes with numbness, which points to sciatica

Common causes of lower back pain

Muscle and ligament strain

The most common cause. It follows lifting, twisting, a sudden movement, unaccustomed exercise or prolonged sitting. Pain is in the muscles beside the spine, worse with movement, and often comes with muscle spasms. It does not cause leg numbness or weakness.

Disc problems

• Herniated disc: the jelly-like center of a disc bulges out and can press on a nerve root, causing leg pain worse than back pain, numbness and tingling. Pain is often worse sitting, bending and coughing. See herniated disc.
• Degenerative disc disease: age-related wear causing recurring aching, often worse with sitting.

Joint causes

• Facet joint pain: arthritis of the small joints at the back of the spine. Worse leaning back, standing and twisting.
• Sacroiliac joint dysfunction: pain over one of the dimples at the base of the spine, sometimes into the buttock and groin. Common in pregnancy and after falls.

Narrowing and slipping

• Spinal stenosis: in people over 60, leg pain, heaviness and numbness on walking or standing, eased by sitting or leaning forward (for example on a shopping cart).
• Spondylolisthesis: a vertebra slipping forward; spondylolysis (a stress fracture) is common in young gymnasts, dancers and fast bowlers.

Inflammatory back pain

Ankylosing spondylitis and related conditions start before age 45, cause stiffness lasting more than 30 minutes in the morning, wake people in the second half of the night, and improve with exercise.

Lower back pain on the right or left side

Kidney pain is felt higher than most muscle pain: just below the ribs at the side of the back (the flank), and it does not change much with movement.

Lower back pain in women

Women can have all the usual causes, plus:

• Period pain (dysmenorrhea), often a dull lower back ache with cramps
• Endometriosis: pain before and during periods, painful sex and sometimes painful bowel movements
• Ovarian cysts and fibroids
• Pelvic inflammatory disease: with fever, discharge and pelvic pain
• Pregnancy: back and pelvic girdle pain affect most pregnant women, especially later in pregnancy. Rhythmic lower back pain in pregnancy can be a sign of labor, including preterm labor.
• Osteoporosis after menopause, increasing the risk of vertebral fractures

Lower back pain with leg pain

Pain that travels below the knee, especially with numbness, tingling or weakness, usually means a nerve root is irritated. The most common cause is a herniated disc in people aged 30 to 50, and spinal stenosis in older adults. Most sciatica settles within 6 to 12 weeks. Weakness, foot drop or any bladder or bowel change needs prompt assessment.

Serious causes (rare)

• Cauda equina syndrome: compression of the nerve bundle at the base of the spine, causing saddle numbness and bladder or bowel problems. Needs emergency surgery.
• Fracture: after trauma or, with osteoporosis, after minor strain.
• Infection: with fever, in people who inject drugs, have diabetes or recently had surgery.
• Cancer spreading to the spine: constant, progressive night pain with weight loss.
• Abdominal aortic aneurysm.

Lower back pain relief

• Keep moving. Gentle walking every few hours speeds recovery. Avoid bed rest.
• Apply heat for 15 to 20 minutes several times a day to relax muscles.
• Anti-inflammatory pain relievers such as ibuprofen or naproxen, following the label dose, for a few days if safe for you. Avoid them with stomach ulcers, kidney disease, heart failure or blood thinners.
• Gentle stretches: knee-to-chest, pelvic tilts, cat-cow and child's pose, within comfort.
• Sleep position: on your side with a pillow between your knees, or on your back with pillows under your knees.
• Avoid heavy lifting for a few days, then build back up.
• Sitting: use a small cushion in the curve of your back and get up every 30 minutes.

For the full range of treatment options, see low back pain treatment and recovery.

Frequently asked questions

How do I know if my lower back pain is serious?

Most lower back pain is not serious. Warning signs include numbness in the groin or buttocks, bladder or bowel changes, leg weakness, fever, unexplained weight loss, a history of cancer, severe night pain or pain after significant trauma. Seek urgent care if any of these are present.

What causes lower back pain on the right side?

Usually a strained muscle or irritated joint on that side. A herniated disc can cause right-sided pain with leg symptoms. Less often, pain comes from the right kidney (stones or infection), the appendix, or in women the right ovary. Fever, urinary symptoms or belly pain point away from the back.

How long does lower back pain last?

Most acute lower back pain improves within 2 weeks and resolves within 6 weeks. If it lasts more than 12 weeks, it is considered chronic. Staying active and returning to normal activities early help recovery.

What is the fastest way to relieve lower back pain?

Combine gentle movement, heat and a short course of an anti-inflammatory such as ibuprofen if safe for you. Gentle stretches and changing position often also help. Avoid bed rest, which slows recovery.

Can kidney problems cause lower back pain?

Yes. Kidney stones cause severe, wave-like pain in the side of the back that spreads to the groin. Kidney infections cause flank pain with fever and urinary symptoms. Kidney pain is usually higher than muscular pain and does not change with movement.