Pain comes in different guises.
It can be physiological, when it has a physiological function and is a warning that something is not right in your body, or it can be pathological, when it becomes chronic and is a disease state in its own right, no longer having a function.
Stephan Schug, director of pain medicine at Royal Perth Hospital, said even with pathological pain there were two distinctive types.
One was neuropathic or nerve pain such as with a spinal cord injury when a person had paralysed legs but they hurt terribly. "The nerves that are damaged are sending wrong signals to the brain," Professor Schug said.
"You have a cut in the spinal cord but the illusion is that the pain comes from the legs, although it comes from the nerve in the spine."
The other type of pathological pain was dysfunctional pain, where the pain was coming from the central nervous system even though there was no nerve damage. "Because of previous injuries, your nervous system becomes hypersensitive," he said.
Examples of dysfunctional pain include chronic back pain, chronic abdominal pain, and fibromyalgia (chronic pain in muscles and soft tissues surrounding joints).
Professor Schug said normal painkillers did not usually work for people with dysfunctional pain. However, it could be helped by medications that strengthened inhibition of the central nervous system, such as a different type of painkiller or some antidepressants.
It could also be treated by drugs that reduced excitation (high sensitisation of the nervous system), such as anticonvulsants. Many chronic pain patients were on one or more of these drugs.
"You need to normalise life in these people again," he said. "Our body's own pain-control mechanisms are dependent on our physical activity so you need to get them moving: that is one of the key ingredients of treatment.
"The less you move, the more pain you get. And then comes the vicious cycle — you are fearful of moving. There is even a word for it, kinesiophobia.
"For example, you mow your lawn because you feel fantastic but it hurts like hell so you decide you can't do that any more and you start then to reduce your physical activity."
One of the first steps was to get such patients into a hydrotherapy pool to get them active again, he said. Other strategies included self-management, coping skills and getting people to take control over their lives again. "All these things are far more important than giving people drugs," Professor Schug said.
Prevention was another important issue. "Preventing excitation seems to be one way of preventing chronic pain," he said.
"You have an injury and you get pain. From an evolution point of view, it was good. If you have a broken arm, the pain gets amplified because you want it to be so strong that you keep the arm still and it heals. When the healing has finished, the input stops and the excitation should stop but it looks now as if in some people the excitation doesn't stop.
"If you give drugs reducing the excitation, it is easier for it to stop."
It was also believed that the use of anticonvulsants before surgery could be protective.
Roger Goucke, director of the pain medicine unit at Sir Charles Gairdner Hospital, said the more effective the management of acute pain was early on, the less likely that chronic pain would develop.
"Most hospitals in Australia now have acute pain services to look after patients admitted to hospital either from the emergency department or after operations," he said.
"They are trying to get people out of bed, control their pain, get them fitter quicker and get them home."
He said self-management was the best way to treat chronic pain.
Back and leg pain were the most common forms of chronic pain.
How to prevent suffering from setting in
•Ensure aggressive and effective management of acute pain.
•Get out of bed as soon as possible after an accident or an operation.
•Keep moving but pace yourself. Don't overdo it but build up fitness gradually with general, regular exercise.
•Maintain a healthy weight because it is then easier to exercise.
•Quit smoking because evidence shows chemicals in cigarettes can be damaging.
•Attend the programs offered by pain medicine units.
•Improve your sleep habits. Go to bed at the same time every night, avoid physical activity before bedtime.
•Avoid sleeping tablets.
•Learn relaxation strategies, such as yoga or tai chi.
•Fish oils and glucosamine are safe and may be useful.
•Paracetamol can be used.
•Low-dose, short-term anti-inflammatory medications are OK but do not use in high doses or long term.Source: Associate Professor Roger Goucke, Professor Stephan Schug
Reasons for chronic pain include
•Back and leg problems
•Neck and arm problems
•Trauma, such as a car accident
•Rheumatoid arthritis or osteoarthritis
•Irritable bowel syndrome
Source: Associate Professor Roger Goucke, Dr Stephanie Davies