Back pain - What is it?

Pain that is only in your back

This is the most common type of back pain. It can either be a sharp pain or a dull pain. It may be mild for some people, but very bad for others. You may have it all the time or it may come and go. You could find that your back pain gets worse when you do certain things or when you change how you are sitting or standing.

It's not usually possible to know what's causing this type of back pain. It could be a strained muscle in your back. (A strained muscle has been overstretched or torn.) But you'll probably get better without knowing why it happened.

Pain down your leg

You may have a pain that's just around your legs or a pain in your back as well. The pain could be in your groin, buttock or upper thigh. Sometimes, it can be below your knee. The pain can be dull and achy and it can move around. It tends to come and go and can vary between being mild to being very bad. You may also get some numbness and tingling.

When you get a pain like this down your leg it is called nerve root pain. You get this type of pain when a nerve coming out from between the bones in your spine gets trapped or damaged (this type of nerve is sometimes called a nerve root). This type of pain is also called sciatica. This is because it is thought to affect the sciatic nerves. (The sciatic nerves are the main nerves that run down your legs. You have one in each leg.)

Sciatica can be caused by a damaged disc (one of the small cushions that protect the bones in your spine) pressing on a nerve. For more information, see our pages on Slipped disc. But it can also be caused by other conditions, such as arthritis or diabetes. Or it can happen if nerves in your spine are damaged when you have surgery on your spine.

Is your back pain acute or chronic?

Your doctor may say your back pain is either acute or chronic. These terms can mean different things to different doctors. But, generally:

• Acute back pain lasts for 12 weeks or less. It is also called short-term back pain.[1]
• Chronic back pain is when you've had pain for more than 12 weeks. It is also called long-term back pain.[2]

If you have had a number of acute bouts of pain, with short periods of relief between them, doctors say that you have recurrent back pain.

Poor posture

Your posture is how you hold different parts of your body when you're resting or doing things. Poor posture may cause back pain in some people.[3] But there hasn't been much research on this, so we can't be sure that poor posture causes back pain. You may get poor posture because of a habit, such as always slumping when you sit in a chair or always standing with your shoulders and back hunched. Poor posture can put pressure on different parts of your back. For example, some muscles may become weaker than others and this means they are more likely to get damaged. If muscles become weak, it can also affect the position of your spine and this can lead to back pain.

Wear and tear on the bones in your spine

As you get older, the discs in your spine can dry out. If this happens, they can't cushion and protect the bones in your spine (the vertebrae) in the way they should. The edges of the vertebrae can then wear away, which can cause back pain. The vertebrae may grow small bony bumps called 'spurs'. These spurs can cause pain by pressing on nerves. The pain can travel down your legs, past your knees and into your feet. The general wear and tear of the vertebrae can also cause back pain.

About 8 in 10 men and 6 in 10 women have some wear and tear of the spine by the time they are 49.[4] By the age of 79, all of us will have some.[4] Your doctor might call this natural wear and tear of the bones osteoarthritis. To learn more, see our pages on Osteoarthritis.

Strained muscles and ligaments

Your back pain may be caused by a strained (stretched or torn) ligament or muscle.[4] This can happen when you lift something heavy or simply move awkwardly. It can also happen when you use a group of muscles that you're not used to using. The ligaments that join bones in your back together are not very elastic, so they can be pulled easily.

Slipped disc

You can get back pain when a disc in your back is damaged. If a disc tears, then its jelly-like centre bulges through the tear and may press on the nerves coming out of your spinal cord. Tissues around the damaged disc may become inflamed and sore. Doctors call this a herniated disc, or you may hear it called a prolapsed or ruptured disc. We have used the term slipped disc because that's the name most people know.

Poor posture or strenuous activity, such as heavy lifting, can damage discs. Sitting down for long periods of time puts more pressure on the discs and vertebrae in the lower part of your back than standing does. This is because your lower back has to support the whole weight of your upper body when you are sitting, with no help from your legs.

Bear in mind that a slipped disc is not a common cause of back pain. Only about 4 in 100 people with back pain caused by a physical problem have a slipped disc.[2]

A slipped disc is the most common cause of the type of pain that goes down your leg (and sometimes below your knee and into your foot). This type of pain is called nerve root pain or sciatica. It may be caused by the disc bulging and pressing on the nerves that join up with the sciatic nerves. (The sciatic nerves are the main nerves in your legs. You have one in each leg.)

You can get a serious complication from a slipped disc. It is called cauda equine syndrome. It happens when bits from a damaged disc press on the bundles of nerves at the base of your spine. You may not be able to walk and you may not be able to control when you go to the toilet. You may also feel numb in your bottom. This is an emergency and you should see your doctor straight away if you get any of those symptoms. You may need emergency surgery to stop the pressure on the nerves.

We look at slipped disc and treatments for it separately. See our articles on Slipped disc to find out more.

Trapped nerves

Your pain may be caused by nerves that have become trapped or damaged where they run out from between the vertebrae. This can happen if you have a disc pressing on one of the nerve roots. Nerves at the base of your spine join up with the sciatic nerves. If a disc is pressing on these nerves, you may feel very bad pain in your legs, buttocks, thighs and feet. This is sometimes called sciatica. It usually gets better on its own. Half of all people with sciatica make a full recovery within a month.[5]

Thinning bones (osteoporosis)

If you have a condition called osteoporosis, the bones in your back become weaker and may break or collapse without you knowing it. This can cause back pain. To learn more, see our articles on Osteoporosis.

Other things that can go wrong

But back pain can sometimes be a symptom of another problem. Some people can get back pain because their spinal canal has narrowed. This is called spinal stenosis and it's common among people older than 60. If you have spinal stenosis you may need more intensive treatment such as surgery.[3]

Another condition that causes back pain is called ankylosing spondylitis. This condition makes the joints in your spine become inflamed, which can cause damage. It usually affects young adults.[2] But it is rare. About 3 in 1,000 people with back pain have this condition.[6]

Back pain can also be caused by serious conditions such as cancer, as well as certain infections, but this is rare.[6] When examining someone with back pain, doctors usually check to see if it could be caused by any other disease. If you're worried or not sure that your doctor has checked for these other causes, then ask.

It's possible that the pain you're experiencing might be referred pain. This means that the problem is somewhere else in your body (in your abdomen, for example), but you're experiencing the pain in your lower back.

To find out more, see More about the causes of back pain.