What is chronic pain?

Chronic pain means that the pain lasts for a long time and comes day after day for weeks, months or years. Chronic pain happens to about one in ten adults in New Zealand.

What is acute pain?

Acute pain just means that the pain has begun recently. It does not always mean that a pain is severe.

(For more on how pain is generated in the body, see our topic on Pain)

What sorts of problems cause chronic pain?

Nerve, head and spinal injuries, cancer, arthritis, angina, fibromyalgia, repetitive strain injury (RSI, or OOS), irritable bowel syndrome, migraine, shingles, the after-effects of surgery and back pain can all cause chronic pain.

Why does pain become chronic?

When an injury or disease causes severe pain for a long time, the spinal cord and the brain change, in the same way your computer changes when you install a new program.

When pain lingers on long after the damage should have healed, it does so because the wiring that carries the messages to the brain is not working properly. Sometimes the "computers" or "exchanges" controlling the messages in the spinal cord do not work properly and they send a distorted message to the brain. In other cases, a part of the brain that helps you manage pain may have been affected.

Bad pain that lasts a long time seems to "engrave" itself on the spinal cord and brain, so that the pain continues to happen even when the initial injury has healed or problem been solved. It may seem to have "worn a rut" - a pathway from the injured part to your brain.

How can we feel ongoing pain in part of the body and have nothing wrong?

You actually do have something wrong if you have pain. The pain is not imaginary. In the worst and most chronic pains, the problem is actually in the spinal cord.

For example, people can get severe pain after they get shingles. This pain can last for months or even years. Patients may get scars on their skin from this condition. The chickenpox virus infecting a part of your spinal cord causes it. The pain is very severe but you feel the pain on the side of your chest not in the spine!

Also, when you have an injury, the injury heals, but sometimes you may continue to have pain, even after it heals. The pain you experience is really just the message that reaches the brain. If the nerves, or "wiring", to the brain or spinal cord have become faulty, or "static" in the "wires" affects the message, then we may believe we have a pain somewhere when the problem is the damage to the wiring. Often the pain can be as bad as or worse than when you first injured yourself.

Could the doctors be wrong?

Doctors are like most tradespeople; they hear the same stories over and over again. Their experience is a good guide to tell you the cause of the pain. They have usually seen it before many times. The best medical scientists have studied pain for many years and know a great deal about pain and what causes it.

How do you treat chronic pain?

The best way to treat chronic pain is to prevent it. When you have an injury and it causes pain, you should make sure you treat the pain as effectively as possible, right from the beginning. It is not good to put up with too much pain. You should see a doctor if ordinary painkillers do not work.

What medications should I take for chronic pain?

You should see your doctor, who will often tell you to start regularly taking two paracetamol tablets every four hours of the day.

If these do not work well enough your doctor may advise you to take one of the many anti-inflammatory medications available. The next step, if these do not work well enough, is to take codeine or dihydrocodeine (DHC). A combination of regular paracetamol with other pain relief medication also helps.

Codeine and DHC can cause constipation. If you need stronger pain relief, long-acting tramadol works well, it is not addictive and does not cause constipation.

Medications usually prescribed for epilepsy, such as Epilim (sodium valproate), Tegretol (carbamazepine) and Neurontin (gabapentin), help chronic pain caused by nerve damage.

What if I find that paracetamol does not help the pain much?

Most people find that if they take paracetamol every four hours without fail that it does help chronic pain quite well, especially in combination with other painkillers.

How can I sleep if I have chronic pain?

When you have chronic pain, it gets worse if you do not sleep properly. Medications such as Amitrip (amitriptyline) and Norpress (nortriptyline) in small dosages can help you sleep when you have chronic pain. These medications are antidepressants of a type that researchers have proven help you to sleep better and help chronic pain. The dose is only one-fifteenth to one-thirtieth of the dose you need to take to treat depression.

Other types of antidepressants do not help chronic pain, and some types may make chronic pain worse. The doctors do not prescribe antidepressants for chronic pain to treat depression, although many people with chronic pain do get depressed when it carries on for a long period.

Tranquilliser-type sleeping pills are addictive and you should not use them regularly. In extreme cases, doctors can prescribe medications like morphine, but for people without cancer the side effects are usually too bad to want to use this medication.

Are these pain medications addictive?

Codeine, dihydrocodeine (DHC) and morphine can be addictive, but if you take them by mouth for pain, people hardly ever become addicted to them. Paracetamol, anti-inflammatories, tramadol, Epilim, Tegretol, Neurontin, amitriptyline and nortriptyline are not addictive.

Why should I take pain medications?

If you are particularly tough, you may be able to cope with the pain you have and get your body working again without any pills.

But some people suffer pain so badly they cannot move without experiencing pain. The secret to recovering from chronic pain is to understand that you will not do any damage by using the painful part of your body. The more you can make the painful body part work, the quicker it will get better. Most people need pain relief to help them do this.

Some people find that they can use the painful body part, but afterwards, or the next day, they get bad pain. This is one reason why regular dosages of paracetamol and anti-inflammatory medications, and long-acting medications like tramadol and DHC help chronic pain, because they will be working when the pain comes on after you exercise.

Will pain medications completely fix my chronic pain?

No, the pain relievers only reduce the pain to a level where you can exercise and use your body properly. It is exercise and re-training the injured part of your body that cures the chronic pain, in many cases completely. Do not rely on medications to fix chronic pain and complain when they do not.

What can I do for myself if I have chronic pain?

The most important thing a person with chronic pain can do is improve their fitness and help the injured part of their body to work as normally as possible. If you have chronic pain, you often favour the injury and this makes the problem worse.

You should give up smoking. You should take as much pain relief medication as you need to cope with exercise, physiotherapy and normal daily activities. You should get regular physical exercise and become physically fit. Fit sportspeople almost never get chronic pain problems. If you have chronic pain, you should try to overcome it by using the painful part as much as you can.

Do not give up hope. Every person who suffers chronic pain can get better. Even if the pain itself does not improve much, they can learn how to cope with the pain better.

This article was written by Dr Leo Revell, a Waikato GP and member of the board of trustees of the Migraine Sufferers' Support Group. This article was originally published in the Waikato Times newspaper. Reviewed by everybody, December 2003.