Signs and symptoms of back pain can include:

• Muscle ache

• Shooting or stabbing pain

• Pain that radiates down your leg

• Pain that worsens with bending, lifting, standing or walking

• Pain that improves with reclining

Back pain that comes on suddenly and lasts no more than six weeks (acute) can be caused by a fall or heavy lifting. Back pain that lasts more than three months (chronic) is less common than acute pain.

Back pain often develops without a cause that your doctor can identify with a test or an imaging study. Conditions commonly linked to back pain include:

• Muscle or ligament strain. Repeated heavy lifting or a sudden awkward movement can strain back muscles and spinal ligaments. If you're in poor physical condition, constant strain on your back can cause painful muscle spasms.

• Bulging or ruptured disks. Disks act as cushions between the bones (vertebrae) in your spine. The soft material inside a disk can bulge or rupture and press on a nerve. However, you can have a bulging or ruptured disk without back pain. Disk disease is often found incidentally when you have spine X-rays for some other reason.

• Arthritis. Osteoarthritis can affect the lower back. In some cases, arthritis in the spine can lead to a narrowing of the space around the spinal cord, a condition called spinal stenosis.

• Skeletal irregularities. A condition in which your spine curves to the side (scoliosis) also can lead to back pain, but generally not until middle age.

• Osteoporosis. Your spine's vertebrae can develop compression fractures if your bones become porous and brittle.

Anyone can develop back pain, even children and teens. These factors might put you at greater risk of developing back pain:

• Age. Back pain is more common as you get older, starting around age 30 or 40.

• Lack of exercise. Weak, unused muscles in your back and abdomen might lead to back pain.

• Excess weight. Excess body weight puts extra stress on your back.

• Diseases. Some types of arthritis and cancer can contribute to back pain.

• Improper lifting. Using your back instead of your legs can lead to back pain.

• Psychological conditions. People prone to depression and anxiety appear to have a greater risk of back pain.

• Smoking. This reduces blood flow to the lower spine, which can keep your body from delivering enough nutrients to the disks in your back. Smoking also slows healing.