What is chronic pain?

Summary

  • Chronic pain is pain that continues beyond the time expected for a painful condition or injury to heal, usually about 3 months. It is different from acute pain.
  • Chronic pain can be associated with chronic conditions but in many cases no specific cause can be found. It is thought that chronic pain occurs because the nerves and spinal cord become over sensitive.
  • Chronic pain is complex to treat but there are things you can do, with help from healthcare professionals, to achieve your goals despite being in chronic pain.

Chronic pain, also called persistent pain, is pain that continues beyond the time expected for a painful condition or injury to heal.1,2 If you have had pain for most days of the week for over 3 months it is considered to be chronic pain.2,3

Chronic pain is different from acute pain

Click to expand Acute pain: Pain messages travel from the nerves to the brain to warn of damage

Acute pain: Pain messages travel from the nerves to the brain to warn of damage
Copyright: Matthew Cole/shutterstock.com

Everybody feels pain at some time. When you are injured, or if you have certain medical conditions, nerves called nociceptors send messages to your spinal cord, which then sends them on to your brain.2,4 Your brain reacts to these messages and you feel pain.4 The pain you feel when you have an injury, or a disease or condition that causes damage to your body, is called acute pain.1 The term 'acute pain' means pain that started recently and is expected to ease over time as the injury or condition heals. It does not refer to how bad the pain is or how serious the problem is.

Although unpleasant, acute pain is a normal protective mechanism.2,5 Acute pain is an early warning signal to reduce damage to our bodies, for example when we touch something that is sharp or too hot, or if we break a bone.5 Acute pain can be severe, but it lessens as the injury or condition is treated and the damage heals.2

The difference between acute and chronic6 pain is important, as different approaches are needed for treatment and management.7

Chronic pain is complex

Pain used to be seen as only a symptom of underlying disease or condition3 and people with cancer, for example, can have long-lasting pain as a result of the cancer causing pressure in the body and bones.2 However, although chronic non-cancer pain can be associated with chronic conditions such as arthritis, sciatica or low back pain, in many cases no specific ongoing injury or disease can be found as a cause.6,10

It can help chronic pain management if it is approached as a chronic medical condition, not just a symptom of something else.7-9 

Even when there is an underlying painful condition, the level of pain you feel may be out of proportion to any damage or continuing harm to your body.7,11 This is what can make living with chronic pain so difficult. It can be a challenge to understand why there is so much ongoing pain and discomfort, which isn't serving a useful purpose and doesn't seem to be able to be relieved.2

What causes chronic pain?

It is thought that chronic pain occurs because the nerves and spinal cord become over sensitive and magnify messages when there is no active damaging stimulus. When the nerve messages reach the brain it thinks there is harm and reacts by feeling pain – even when there is no injury.2,4,9

Neuropathic pain

Neuropathic pain is a type of chronic pain that occurs following damage to the nervous system itself. It is also called nerve pain or nerve-damage pain. The sensations associated with this type of pain are described as burning or shooting pains. The skin can be numb, tingling or extremely sensitive.2

The brain can change too

When chronic pain continues for some time, the brain can start to react to messages from other parts of the body near the site of the now healed damage and you feel pain in those areas too, making the situation worse. These changes in the brain are called neuroplasticity.4

The good news is that this ability of the brain to change means that there are ways you can 're-train' your brain to reduce the sensation of pain.4,9

Chronic pain is complex and can be difficult to treat, and you may feel frustrated, hopeless and disappointed. However, there are things you can do, with help and guidance from healthcare professionals, to achieve your goals despite being in chronic pain.2

Find out more

References
  1. Pain Australia. Fact sheet 1: The nature and science of pain. Waverly, NSW: Pain Australia. [Full text] (accessed 11 May 2015)
  2. Siddall PJ, McCabe R and Murray R. The pain book: finding hope when it hurts. ed. Sydney, Australia: Hammond Press, 2013.
  3. Pain Australia. Fact sheet 7: Managing chronic pain. Waverly, NSW.: 2014. [Full text] (accessed 11 May 2015).
  4. Butler D and Moseley L. Explain pain. 2nd ed. Adelaide, Australia: NoiGroup Publications, 2013.
  5. Woolf CJ. What is this thing called pain? J Clin Invest 2010;120:3742–4.
  6. Australian and New Zealand College of Anaesthetists. National pain strategy: pain management for all Australians. Melbourne: ANZCA, Faculty of Pain Medicine, Australian Pain Society, Chronic Pain Australia, 2010. [Full text] (accessed 11 May 2015)
  7. Siddall PJ and Cousins MJ. Persistent pain as a disease entity: implications for clinical management. Anesth Analg 2004;99:510–20.
  8. Cohen ML. Principles of prescribing for persistent non-cancer pain. Aust Prescr 2013;36:113–5. [Online]
  9. Hayes C, Naylor R and Egger G. Understanding chronic pain in a lifestyle context. Am J Lifestyle Med 2012;6:421–8.
  10. Woolf CJ. Central sensitization: implications for the diagnosis and treatment of pain. Pain 2011;152:S2–15.
  11. Turk DC, Wilson HD and Cahana A. Treatmnent of chronic non-cancer pain. Lancet 2011;377:2226–35. [Pubmed]