Acute low back pain

Acute low back pain is pain in the lower back that began recently. “Acute” describes how long it has been present, not how severe it is.

Pain may start after lifting, twisting, exercising, or falling, or appear without a clear trigger. Often, it is not possible or necessary to identify one injured muscle, joint, or disc.

Most episodes improve over days to a few weeks. Serious causes are uncommon, but certain symptoms need urgent assessment.

Pain that travels into a leg may involve an irritated spinal nerve. This is sometimes called sciatica, especially when pain follows the back of the leg. Leg symptoms do not automatically mean there is serious nerve damage.

You may notice:

• A dull ache, tightness, or stiffness
• Sharp pain during bending, lifting, or twisting
• Muscle spasms
• Pain that is worse after sitting or staying still
• Pain spreading into a buttock or leg
• Tingling or numbness in part of a leg

Movement may be uncomfortable, but pain with movement does not always mean that you are causing further injury.

Tell a healthcare professional about leg weakness, numbness around the genitals or buttocks, fever, urinary symptoms, or pain that repeatedly wakes you. These details may affect how quickly you need assessment.

Most acute low back pain is nonspecific. It may come from muscles, ligaments, joints, or discs, but no single source can be confirmed.

Common triggers include lifting, unfamiliar activity, prolonged sitting, sudden twisting, or doing more physical work than usual. Stress, poor sleep, and worry can increase muscle tension and make pain feel stronger, but this does not mean the pain is imaginary.

An irritated or bulging spinal disc may inflame or press on a nearby nerve, causing pain, tingling, or numbness down one leg.

Less common causes include a spinal compression fracture, inflammatory arthritis, kidney problems, or shingles. Rare but urgent causes include infection, pressure on the nerves at the bottom of the spine, or pain referred from a major blood vessel or abdominal organ.

Call emergency services or go to an emergency department now if back pain occurs with:

• New inability to urinate or new loss of bladder or bowel control
• New numbness around the genitals, inner thighs, or buttocks
• Rapidly worsening weakness in one or both legs
• Severe chest or abdominal pain, fainting, or difficulty breathing
• A major crash, fall, or other high-force injury

Bladder changes, saddle-area numbness, and leg weakness can indicate serious pressure on spinal nerves. Prompt assessment matters.

Seek same-day medical advice if you have fever or chills, feel seriously unwell, or have severe pain after a smaller fall when you have osteoporosis or fragile bones. Also seek prompt advice if you have a weakened immune system, inject drugs, recently had a serious infection or spinal procedure, or have a history of cancer.

Book a routine appointment if pain is not starting to improve after one to two weeks, keeps returning, limits normal activity, or continues for several weeks. Arrange assessment sooner if leg pain, numbness, or weakness is developing.

A healthcare professional will ask when the pain began, what affects it, and whether it spreads into your legs. They may also ask about injuries, fever, bladder or bowel changes, cancer, infections, osteoporosis, medicines, and other conditions.

An examination may check how you walk and move. Leg strength, sensation, and reflexes may be tested if nerve irritation is possible. Your abdomen or hips may be examined if another source is suspected.

Most people with new low back pain do not need an X-ray, CT scan, or MRI. Imaging often shows age-related changes also found in people without pain. It may be appropriate after significant trauma, when warning symptoms are present, or when persistent symptoms could change treatment. Blood or urine tests are used when infection, inflammation, kidney disease, or another specific cause is suspected.

Continue ordinary activities within tolerable limits. Brief rests can help during a flare, but prolonged bed rest may increase stiffness and slow recovery. Temporarily change tasks that clearly worsen pain, then gradually build activity back up.

Heat may ease stiffness or muscle spasm. Some people prefer a wrapped cold pack after a recent strain. Protect your skin and use whichever feels more comfortable.

Gentle walking and relaxed movement are reasonable starting points. Stop and seek advice if movement causes new weakness, spreading numbness, or loss of bladder or bowel control.

Anti-inflammatory medicines such as ibuprofen or naproxen may help but are not suitable for everyone. Check with a pharmacist or clinician if you have kidney or heart disease, a history of stomach ulcers, take blood-thinning medicine, or are pregnant. Follow product instructions and do not combine products containing the same ingredient.

Prescription pain medicines are not routinely needed. Opioids like oxycodone or morphine can cause drowsiness, constipation, dependence, and overdose, so discuss their risks and limited role with a prescriber.

Many episodes begin to settle within several days and improve further over the next few weeks. Recovery can be uneven; a more painful day does not necessarily mean damage is worsening.

Gradually returning to work, exercise, and usual activities can support recovery. Temporary adjustments to lifting, sitting, or demanding tasks may help.

Low back pain can return. Regular activity, changing position during long periods of sitting, and preparing gradually for heavier tasks may reduce its effect. Persistent pain needs reassessment, especially if symptoms change or affect sleep, mood, mobility, or work.

Should I stay in bed?

Usually not. Brief rest may help when pain is intense, but gentle movement and normal activity are generally better than prolonged bed rest.

Do I need a scan?

Most new episodes do not require one. A scan is more useful when there are warning symptoms, significant trauma, or persistent symptoms for which the result would change treatment.

Does pain down my leg mean a slipped disc?

Not always. Several structures can irritate a nerve, and symptoms may improve without surgery. New or worsening weakness, saddle numbness, or bladder changes need urgent assessment.

Is it safe to exercise?

Gentle activity is usually reasonable if it does not cause new neurological symptoms. Start below your usual level and increase gradually as pain allows.