Low Back Pain: Causes, Treatment and When to Worry
Most low back pain is non-specific, which means it comes from the muscles, joints and ligaments of the back rather than from a disease, and it eases within four to six weeks whether or not you have a scan. The single most useful thing you can do is keep moving; bed rest beyond a day or two makes recovery slower, not faster. Simple pain relief, heat and a gradual return to normal activity are the mainstay, and structured exercise helps the episodes that drag on. An X-ray or MRI adds nothing to an ordinary first episode, because wear-and-tear changes show up on the scans of large numbers of people who have no pain at all. Back pain does need urgent assessment if you lose control of your bladder or bowels, go numb around the groin or inner thighs, develop weakness in both legs, run a fever or night sweats with the pain, are losing weight without trying, or the pain follows a fall.
Health writers · Aslam Clinic
What low back pain actually is
The lower back carries the weight of the upper body and lets it bend and twist, using five stacked bones, the shock-absorbing discs between them, small joints at the back of each pair, and a thick sheet of muscle and ligament. Any of those can hurt, and in most people several are involved at once rather than one broken part.
That is why doctors call the great majority of cases non-specific low back pain. It does not mean the pain is imaginary. It means no single structure can honestly be blamed, and that the treatment is the same either way. Roughly one episode in twenty has a specific cause: a compressed nerve, a fracture, an infection, of the spine, or, rarely, a cancer that has spread to bone.
Most episodes improve substantially inside six weeks, and around one person in five still has some pain at a year. Knowing that in advance matters, because expecting a two-day cure and not getting one is itself a reason people stop moving, start worrying, and end up in the slow group.
What sets an episode off
Often nothing dramatic — bending to pick up a child, a bucket or a prayer mat, or straightening after a long stretch at a desk. The trigger is usually the last small demand on a back that was already tired or unaccustomed to the movement, not the whole cause.
- Sitting for hours without changing position, particularly on a low sofa or a car seat with no lumbar support.
- Lifting with a bent back and straight legs, or lifting while twisting.
- A sudden increase in load — a house move, a wedding week, a new job on your feet.
- Weak trunk and hip muscles, which leave the spine doing work the muscles should share.
- Excess weight, which loads the lumbar discs with every step. A rising is one of the few risk factors you can change.
- Smoking, consistently associated with more back pain and slower recovery.
- Stress, low mood and poor sleep, which genuinely amplify pain signals. That is biology, not weakness of character.
Sciatica and the so-called slipped disc
Sciatica is pain travelling from the lower back or buttock down the back of one leg, often past the knee, sometimes with pins and needles, numbness or foot weakness. It is a symptom of an irritated nerve root, usually because part of a disc has bulged against it. Discs do not slip out of place; the outer ring weakens and the softer centre pushes into it, which is a very different picture from the one the phrase suggests.
Around three-quarters of people improve substantially within six to twelve weeks with pain relief, movement and time, and the bulge often shrinks on its own. Surgery is considered when severe pain persists past that point, or when weakness is progressing — not because a scan looks alarming in someone who is recovering well.
Do you need an X-ray or an MRI?
For ordinary back pain, no — and this is a place where doing less is genuinely better care. Imaging people without warning signs does not improve pain, function or recovery time in trials, a plain delivers a meaningful radiation dose to the pelvis for almost no diagnostic return, and any scan will find something. Studies that scanned people with no back pain at all found disc degeneration in about a third of adults in their twenties and in more than nine in ten by their seventies. These findings are the spinal equivalent of grey hair, and reading them as the cause of today's pain leads to unnecessary worry, unnecessary rest and occasionally an unnecessary operation.
| Situation | Is a scan useful? | Why |
|---|---|---|
| First episode, no red flags, improving | No | Management is the same whatever the scan shows, and incidental findings cause harm. |
| Back pain plus sciatica, improving | Not yet | Most nerve-root pain settles. Scan only if an injection or operation is genuinely planned. |
| Pain persisting past 6 weeks despite proper treatment | Sometimes | Reasonable if it would change the plan, usually before a specialist referral. |
| Bladder or bowel control lost, saddle numbness, both legs weak | Yes, urgently | Same-day to look for compression of the nerve bundle. |
| Fever, night sweats, weight loss, night pain | Yes | Looking for spinal infection or tuberculosis. Blood tests and , not a plain film. |
| Known cancer, or severe pain after minor trauma over 60 | Yes | Looking for a fracture or spread to bone. A or answers this; an X-ray often misses it. |
What genuinely helps
| Approach | What it does | Worth doing? |
|---|---|---|
| Staying active | Maintains strength and confidence; shortens time off work | Yes — the most effective single step. Modify what you do, do not stop. |
| Reduces pain and modestly for a few weeks | Yes, briefly, if your stomach, kidneys, blood pressure and heart allow it. | |
| Paracetamol | Mild pain relief; weak evidence in back pain specifically | Reasonable and low-risk, especially where anti-inflammatories are unsafe. |
| Heat | Eases muscle spasm in the first week | Yes. Cheap, safe, and people find it helps. |
| Structured exercise or physiotherapy | Builds trunk and hip strength; addresses fear of movement | Yes, especially past two to three weeks or for repeat episodes. |
| Manual therapy or massage | Short-term pain relief | Only as part of a package that includes exercise, not on its own. |
| Bed rest | Nothing useful; muscles decondition within days | No. Beyond a day or two it delays recovery. |
| Lumbar support belts | Feel supportive; no evidence of benefit | No, other than briefly for a specific heavy task. |
| Opioid painkillers | Pain relief at the cost of dependence, constipation and drowsiness | Not routinely. For days rather than weeks, and only on prescription. |
| Steroid injections into the spine | Can settle severe nerve-root pain for weeks to months | Only for sciatica that has failed everything else, after specialist assessment. |
On pain relief specifically: paracetamol for an adult is usually 500 to 1000 mg up to four times in twenty-four hours, and never more than 4 g in a day. The commonest way people exceed that here is by taking a plain paracetamol tablet alongside a combination cold or pain preparation that already contains it, so read the box. If you have liver disease, drink alcohol regularly or weigh under about 50 kg, the safe maximum is lower and your doctor should set it. such as ibuprofen, diclofenac or naproxen work better for back pain but carry a real risk of stomach bleeding, kidney strain and raised , so anyone with , ulcers, kidney disease, heart failure or uncontrolled hypertension should take them only on a doctor's advice.
What to do in the first week
- Keep moving within the limits of the pain. Short, frequent walks beat long rests; aim to be up every half hour.
- Change position often. If your work is at a desk, stand every twenty minutes.
- Use heat for the spasm — fifteen to twenty minutes with a cloth between the heat and your skin.
- Take pain relief on a schedule for the first few days, not on demand. Staying ahead of the pain is what lets you keep moving.
- Sleep in whatever position hurts least — on your side with a pillow between the knees, or on your back with one under the knees.
- Return to normal activity before the pain has fully gone. Waiting until it is zero turns a three-week problem into a three-month one.
Making the next episode milder
- Regular exercise of almost any kind. Walking, swimming, cycling, yoga and gym work all reduce recurrence, and the differences between them are small. The one you will keep doing is the best one.
- Trunk and hip strength. Bridges, side planks and sit-to-stands from a chair, a few times a week, protect the back better than any belt or mattress.
- Weight and smoking, both linked to more frequent and more persistent episodes, and both within your control in a way your spine's shape is not.
- Lifting technique — bend the hips and knees, keep the load close, turn your feet rather than twisting. This matters most for what you lift many times a day.
- Sleep and mood. Poor sleep lowers pain thresholds measurably, so treating back pain without addressing them is treating half the problem.
When to see a doctor
Beyond the emergency signs above, book an appointment if the pain has not started improving after two to three weeks of sensible self-care, if it stops you working or sleeping, if it travels below the knee with numbness or weakness, or if this is your third or fourth episode in a year. Persistent back pain is worth assessing not because something sinister is likely, but because a structured exercise plan works far better than another year of painkillers.
Bring a short history: when it started, what you were doing, what makes it better and worse, whether it travels, and what you have already tried. That is more useful than any scan you might arrive holding. If the pain is in your knee rather than your back, or both, see our guide to knee osteoarthritis.
Common questions
Still not sure what to do?
Reading about a symptom only goes so far. A doctor who can ask you questions and examine you will get further in ten minutes than any article can.
