Understanding low back pain and sciatica

Why low back pain happens, why most of it gets better, why scans are rarely needed early, and what sciatica really is. A calm, plain-language guide.

6 min read · last reviewed October 1, 2026

Maybe you bent down to pick up a laundry basket and felt a sudden grab in your lower back. Maybe the pain crept in over a few days of long hours at a desk. Either way, back pain can be scary. It can make it hard to sit, stand, sleep or even put on your socks.

Here is the good news: low back pain is one of the most common health problems in the world, and most of it gets better. This guide explains what is going on, so you can worry less and move more.

How common is it?

Very. Most adults will have low back pain at some point in their lives. It affects people of every age, shape and fitness level, including athletes. It is one of the most common reasons people see a doctor or miss work.

Most new episodes improve a lot within a few weeks. For some people, the pain lingers longer or comes back from time to time. That is common, too, and there is plenty you can do about it.

"Non-specific" back pain: real pain, no serious damage

For about 9 in 10 people, doctors can't point to one exact cause. This is called non-specific low back pain. The name can sound like a shrug, but it is actually reassuring. It means your doctor has checked for the rare serious causes, such as a broken bone, an infection or cancer, and found no sign of them.

Your back is a strong, well-built structure. It is made of bones (vertebrae), discs that act like tough spacers, joints, ligaments and many layers of muscle. Non-specific pain usually comes from these tissues being irritated, strained or extra sensitive. It is not a sign that your spine is fragile or "out of place."

Something you can do today: Remind yourself that your back is strong. Most back pain is not a sign of serious harm.

Why does it hurt so much, then?

Pain is your body's alarm system. It is meant to protect you. But the alarm can be very sensitive, especially in the first days. It can ring loudly even when there is little or no damage.

Many things can turn the volume of pain up or down:

• Turning it up: poor sleep, stress, worry about what the pain means, low mood, being tired, and avoiding movement for a long time.
• Turning it down: gentle movement, good sleep, feeling in control, reassurance, heat, and doing things you enjoy.

This doesn't mean the pain is "in your head." All pain is real. It means your brain, nerves and body all work together to create pain, so there are lots of ways to help it settle.

Do I need an X-ray or MRI?

Most people with low back pain don't. Guidelines in the UK, the U.S. and Canada advise against routine scans for back pain without warning signs. Here is why:

• Scans rarely change treatment. The plan is usually the same: stay active, exercise and manage the pain.
• Scans show lots of normal changes. Disc bulges, "wear and tear" and disc "degeneration" are very common in people with no back pain at all. One large review found that disc degeneration shows up in about a third of pain-free 20-year-olds, and in most pain-free people over 60. These changes are a bit like grey hair or wrinkles on the inside.
• Scary words can slow recovery. Being told you have a "degenerated" spine can make people afraid to move, which can make pain last longer.

Your doctor will suggest a scan if you have warning signs (see our guide Back pain warning signs), or if you are being considered for an injection or surgery.

What is sciatica?

Sciatica is pain that travels from the lower back or buttock down the back of one leg, often below the knee and sometimes into the foot. You may also feel:

• Sharp, shooting or burning pain
• Pins and needles or numbness
• Some weakness in the leg or foot

The pain can be worse when you cough, sneeze or sit for a long time. Often the leg hurts more than the back.

Sciatica happens when a nerve root in the lower back is irritated or squeezed. The most common cause is a bulging (herniated) disc. Less often, especially in older adults, it is caused by narrowing of the spaces around the nerves (spinal stenosis).

The encouraging part: most sciatica gets better on its own over a few weeks to a few months. The body can often reabsorb part of a bulging disc over time. Staying as active as you can helps.

Something you can do this week: If you have sciatica, try changing position often. Short walks are usually easier than long periods of sitting.

When back pain might be something else

Rarely, back pain is a sign of a problem that needs fast care. These include:

• Cauda equina syndrome: new problems with your bladder or bowels, or numbness around your genitals or bottom. This is an emergency. Go to an emergency department right away.
• Pain with fever, or after a serious accident.
• Pain if you have had cancer, or are losing weight without trying.
• Leg weakness that is getting worse.

Our guide Back pain warning signs explains these in more detail. Most people will never have them, but it helps to know them.

A hopeful outlook

Back pain can feel like it will never end, especially on day two. But for most people it eases with time, movement and patience. Even if pain lasts longer or comes back, the right mix of exercise, self-care and support can help you get back to the things that matter to you.

Something you can do today: Take a short, easy walk, even 5 minutes. Gentle movement is one of the best things for a sore back.

Questions to ask your care team

• What do you think is causing my back pain?
• Do I have any warning signs that need more tests?
• Do I need a scan? If not, why not?
• Is my leg pain sciatica? What should I watch for?
• How long do you expect it to take to improve?
• What activities are safe for me right now?

This article is general information, not medical advice. Talk with your health care team about your own situation. In an emergency, call 9-1-1 or your local emergency number.

In an emergency, call 9-1-1 or your local emergency number.

General information, not medical advice. It does not replace your own care team. If you think you or someone else is having a medical emergency, call 9-1-1 or your local emergency number. If you are in crisis or thinking about suicide, call or text 9-8-8 (Canada and the US).

Back to Low back pain