What is a slipped disc?

What the term means

Between the bones of your spine (the vertebrae) sit rubbery cushions called discs. Each one has a soft, jelly-like center and a tougher outer layer. A slipped disc happens when part of that soft center pushes out through a tear in the outer layer. Doctors may call it a herniated, prolapsed or ruptured disc, and these terms are used for the same thing.

"Slipped" is everyday wording, and the sources describe the problem as a bulge or leak of the disc's soft center. Mayo Clinic notes that a herniated disc can occur in any part of the spine but is most common in the lower back, and that it can also happen in the neck.

Symptoms, and why some people have none

What you feel depends on where the disc is and whether it presses on a nerve. The NHS lists lower back pain, numbness or tingling, muscle weakness, and pain in the buttocks, hips or legs when the sciatic nerve is involved. That leg pain pattern has its own name, covered in What is sciatica?

In the neck, Mayo Clinic says a herniated disc typically causes the most pain in the shoulder and arm, sometimes sharp or burning, and often worse when you cough, sneeze or move a certain way. Most of the time only one side of the body is affected.

Not every slipped disc hurts. The NHS states that not all slipped discs cause symptoms and that many people will never know they have slipped a disc. This is one reason a scan can show a disc finding that has nothing to do with the pain you came in with, a point explored in Are disc changes on an MRI normal?

Why it happens

Age is a large part of the story. Mayo Clinic explains that discs become less flexible over time and can tear more easily, even with small movements such as bending or twisting. The NHS lists ageing, lifting heavy objects the wrong way, exercising too hard, long periods of sitting or driving, and being inactive or overweight as possible contributors. The NHS also names smoking, saying nicotine weakens disc tissue. Often, as Mayo Clinic puts it, people do not know what caused theirs.

What usually happens next

According to the NHS, a slipped disc usually gets better slowly with rest, gentle exercise and painkillers. Mayo Clinic says symptoms typically improve over time and that most people do not need surgery. The NHS adds that a GP may refer someone to a specialist to discuss surgery if symptoms have not improved with other treatments or if muscle weakness or numbness is getting worse. What is offered varies between countries and between clinicians, so a person's own clinician is the right guide.

Back pain without leg or arm symptoms is a different situation in many cases, and What causes most low back pain? describes that more common picture. Related questions about discs and nerves are gathered under Discs and nerves.

When to get help

The NHS advises seeing a GP if you have back pain and painkillers are not helping, the pain is not getting better after a few weeks, or you have a very high temperature, unexplained weight loss, a swelling in the back, or pain that is worse at night. Mayo Clinic suggests contacting a healthcare professional if neck or back pain spreads into an arm or leg, or if you have numbness, tingling or weakness.

Some signs call for emergency care. The NHS says to call 999 or go to A&E (use your local emergency number elsewhere) for back pain with numbness around the bottom or genitals, being unable to pee, losing feeling in one or both legs, loss of bladder or bowel control, or pain that began after a serious accident. Mayo Clinic describes pressure on the whole nerve bundle at the base of the spine, called cauda equina syndrome, as rare but a medical emergency. More on this is in When is back pain an emergency? Practice varies by country and by clinician.