Chronic Pain: What It Is, Why It Lasts and What Helps

What is chronic pain?

Chronic pain is pain that persists or recurs for longer than three months. It’s defined this way in the International Classification of Diseases, which since 2019 has recognised chronic pain both as a symptom of other conditions and, in some cases, as a condition in its own right.

The International Association for the Study of Pain describes pain as an unpleasant sensory and emotional experience, linked to actual or possible tissue damage. Pain is always real, whether or not a scan shows a cause.

How common is it?

Very. The Australian Institute of Health and Welfare estimates that 1.6 million Australians aged 45 and over, about one in five, were living with chronic pain in 2016. Chronic pain is one of the leading causes of disability worldwide.

Types of chronic pain

• Chronic primary pain: pain that isn’t better explained by another condition and is the main problem, such as chronic widespread pain and fibromyalgia, many cases of chronic low back pain, and chronic pelvic pain.
• Chronic secondary pain: pain that is part of another condition, such as arthritis, endometriosis, cancer, nerve damage or an injury.

Many people have more than one type at once.

Why does pain last?

Acute pain is a useful warning signal. With chronic pain, the alarm system itself can become more sensitive. The nerves and brain amplify signals, so pain is produced more easily and lasts longer. This is called central sensitisation. See central sensitisation explained.

Other things also turn pain up:

• poor sleep
• stress, worry and low mood
• inactivity and loss of fitness
• fear that movement will cause damage
• other health problems

This doesn’t mean pain is “in your head”. It means the nervous system, body and life circumstances all shape how much pain you feel, and each is a place where change can help.

What helps chronic pain?

• Understanding pain. Learning how pain works reduces fear and makes it easier to move.
• Exercise and movement, built up gradually. See chronic pain management.
• Psychological approaches, which help with coping, mood and getting back to life. See why a psychologist can help.
• Better sleep. See chronic pain and sleep.
• Treating the underlying condition where there is one.
• Medicines have a role for some people and some conditions, but on their own they rarely solve chronic pain, and some carry significant risks with long-term use.

When to see a doctor

See a GP if pain has lasted more than three months, keeps coming back, or is affecting your sleep, mood, work or relationships. Get urgent help for new pain with weakness or numbness, loss of bladder or bowel control, high fever or chest pain.

References

1. Treede RD, Rief W, Barke A, et al. Chronic pain as a symptom or a disease: the IASP Classification of Chronic Pain for the International Classification of Diseases (ICD-11). Pain. 2019;160(1):19-27.
2. Raja SN, Carr DB, Cohen M, et al. The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises. Pain. 2020;161(9):1976-1982.
3. Cohen SP, Vase L, Hooten WM. Chronic pain: an update on burden, best practices, and new advances. Lancet. 2021;397(10289):2082-2097.
4. Nicholas M, Vlaeyen JWS, Rief W, et al. The IASP classification of chronic pain for ICD-11: chronic primary pain. Pain. 2019;160(1):28-37.
5. Blyth FM, March LM, Brnabic AJ, et al. Chronic pain in Australia: a prevalence study. Pain. 2001;89(2-3):127-34.
6. Australian Institute of Health and Welfare. Chronic pain in Australia.
7. healthdirect. Chronic pain.