Acute lower back pain: a case-based approach

The case: a sudden painful back

A 40-year-old lifts a heavy box, feels a sharp twinge in the lower back, and by the next morning can barely straighten up. The pain is a dull ache with spasms, worse on moving from sitting to standing, but eases a little once they get going. There is no numbness, no leg weakness, and no bladder or bowel trouble. This picture is extremely common and is usually called non-specific lower back pain, meaning no single structure can be pinpointed and no serious disease is present. It is frightening because it is painful and limiting, but it does not mean the spine is damaged or crumbling. The first job for a clinician is to reassure, check for red flags, and encourage a return to normal movement.

Why most back pain is not serious

The lower back is a strong, well-designed structure, and pain does not equal harm. In most cases of acute back pain, scans are not needed and can even be unhelpful, because they often show harmless age-related changes that are present in pain-free people too. NHS and NICE guidance stresses that the vast majority of episodes settle within about six weeks, and that staying active speeds recovery. Bed rest weakens muscles, stiffens joints, and prolongs pain. The message professionals give is hopeful and practical: hurt does not mean harm, movement is medicine for the back, and most people get back to normal life. Understanding this reduces fear, which itself is one of the factors that can make back pain last longer.

Self-care that helps recovery

The mainstay of managing acute back pain is to keep moving and continue everyday activities as much as the pain allows, adjusting rather than stopping them. Gentle walking, changing position often, and gradually building back up all help. Staying at or returning to work, even on lighter duties, is linked with better recovery. Simple pain relief from a pharmacy, used as directed, can make movement easier; a community pharmacist can advise what is suitable. Heat, such as a warm bath or a covered heat pack, may soothe muscle spasm. Group exercise, stretching, and strengthening are recommended for pain that lingers. Practising good lifting habits and staying generally active help prevent future episodes. What is not helpful is prolonged bed rest or waiting anxiously for pain to vanish before moving.

Cauda equina and other red flags

A small number of back problems are serious and must not be missed. The most urgent is cauda equina syndrome, where the bundle of nerves at the base of the spine is squeezed. Warning signs include numbness or tingling around the back passage, genitals, or inner thighs (a saddle pattern); difficulty passing urine or a loss of bladder or bowel control; and weakness or numbness in both legs. These are an emergency — phone 999 or go straight to A&E, as delay can cause permanent damage. Other features that need prompt medical assessment include back pain following a serious injury, pain with a fever or unexplained weight loss, pain that is much worse at night, or new back pain in someone with a history of cancer or a weakened immune system.

When to seek help and what to expect

See a GP or physiotherapist, or call NHS 111, if the pain is severe, is not improving after a few weeks, keeps returning, or is stopping you doing everyday things. In England you can often refer yourself to an NHS physiotherapist without seeing a GP first. A clinician will ask about the pain and check for red flags; scans are reserved for when a serious cause is suspected or symptoms persist despite treatment. Most people need reassurance, advice to stay active, and support to manage pain rather than tests or specialist referral. Pain that spreads down a leg with pins and needles (sometimes called sciatica) often still settles with time and exercise. The overall outlook for acute back pain is good, and recovery is the rule rather than the exception.