Some of the most common causes of stress and strain on the spine include:
- Poor posture – slouching in chairs, driving in hunched positions and standing badly
- Lifting incorrectly
- Sleeping on sagging mattresses
- Being unfit
- Generally overdoing it – over tiring muscles and not using a gradually increasing work or sports programme. Not warming up or cooling down before and after exercise will also cause muscle pain
- Inactivity and the wrong sort of movement are usually at the root of simple back pain.
Inactivity makes the muscles go slack and weak so they are unable to support the back properly. This leaves the back more vulnerable to damage when certain movements put too much strain on one area.
Often, the problem is caused by a strain or tear to the muscles, tendons or ligaments around the lower spine. In turn, this can produce painful muscle tension and spasm.
Even a minor problem can cause a lot of pain when you stand, bend or move around. Pain sometimes comes on suddenly, sometimes gradually, but usually it only lasts a few days or up to a week.
Non-specific low back pain
This is the most common type of back pain. About 19 in 20 cases of acute (sudden onset) low back pain are classed as non-specific. This is the type of back pain that most people will have at some point in their life. It is called non-specific because it is usually not clear what is actually causing the pain.
It is thought that in some cases the cause may be a sprain (an over-stretch) of a ligament or muscle. In other cases the cause may be a minor problem with a disc between two vertebrae, or a minor problem with a small facet joint between two vertebrae. There may be other minor problems in the structures and tissues of the lower back that result in pain. However, these causes of the pain are impossible to prove by tests.
Nerve root pain – often called sciatica
This occurs in less than 1 in 20 cases of acute low back pain. Nerve root pain means that a nerve coming out from the spinal cord (the root of the nerve) is irritated or pressed on. Many people call this pressure a trapped nerve. You feel pain along the course of the nerve. Therefore, you typically feel pain down a leg, sometimes as far as to the calf or foot. The pain in the leg or foot is often worse than the pain in the back. The irritation or pressure on the nerve may also cause pins and needles, numbness or weakness in part of a buttock, leg or foot.
About 9 in 10 cases of nerve root back pain are due to a prolapsed disc – often called a slipped disc. A disc does not actually slip. What happens is that part of the inner softer part of the disc bulges out (prolapses) through a weakness in the outer harder part of the disc. The prolapsed part of the disc can press on a nerve nearby. Other less common conditions can cause pressure on a nerve to cause nerve root pain for example piriformis syndrome.
Cauda equina syndrome – rare, but an emergency
Cauda equina syndrome is a particularly serious type of nerve root problem. This is a rare disorder where the nerves at the very bottom of the spinal cord are pressed on. This syndrome can cause low back pain plus: problems with bowel and bladder function (usually unable to pass urine), numbness in the saddle area (around the anus), and weakness in one or both legs. This syndrome needs urgent treatment to preserve the nerves to the bladder and bowel from becoming permanently damaged. Go to A and E immediately if you suspect cauda equina syndrome.
Serious Symptoms in Back Pain
There are several warning signs, known as red flag signs, that may indicate that your back pain is caused by a more serious condition that requires immediate medical help. These include:
- a fever of 38ºC (100.4ºF) or above
- unexplained weight loss
- swelling of the back
- constant back pain that does not ease after lying down
- pain in your chest or high up in your back
- pain down your legs and below the knees
- pain caused by a recent trauma or injury to your back
- loss of bladder control
- inability to pass urine
- loss of bowel control
- numbness around your genitals, buttocks or back passage
- pain that is worse at night