Persistent pain and a sensitised pain system

Persistent pain is defined as pain that is continuous or keeps recurring for more than three months [3][4]. NHI also mentions an interval of three to six months, so the limit is not entirely clear-cut [1].

The Norwegian Institute of Public Health reports that between 35 and 55 percent of Norwegian adults have persistent pain in some form, and that 20 to 30 percent have moderate to severe pain [3]. The condition is also a frequent cause of long-term sick leave and disability [4].

Sundhed.dk describes that pain lasting beyond normal healing is often linked to an oversensitive nervous system. The pain can then continue even though an earlier injury has healed, and it can spread to areas that have never been injured [2].

NHI uses the term nociplastic pain for pain that arises from an altered perception of pain, without clear tissue damage or nerve damage having been found. This is linked to changes in how the nervous and immune systems function, and the pain can become amplified and widespread [1].

The Norwegian Institute of Public Health uses the word pain sensitivity. People with persistent pain have higher pain sensitivity in measurements, but it is unclear whether the pain makes people more sensitive or whether high sensitivity increases the risk of persistent pain. This is an association, not an established cause [3].

The pain can be widespread and have little clear connection to a specific injury [2][4]. Many also have poorer sleep, fatigue and problems with memory and concentration, and some experience low mood or anxiety [1][2].

Persistent pain often leads to avoidance behaviour, isolation and passivity, and affects quality of life [4].

NHI points to several factors that can contribute to the pain continuing. Fear that the pain will get worse with movement can lead to less activity, which in turn can weaken function and amplify the pain. Depression, sleep problems and reduced energy can affect how the pain is experienced, and so can earlier experiences [1].

The relationships are complex and differ from person to person. The sources describe these as factors that can contribute, not as an explanation that applies to everyone.

The GP usually assesses the cause of the pain and decides whether it can be treated [2]. The assessment should be both somatic and psychosocial, and necessary diagnostics should be carried out to identify possible physical causes [4].

The diagnosis is often a symptom diagnosis, because the pain frequently persists without a defined somatic cause [4]. A sensitised pain system should therefore be considered only after other possible causes have been assessed.

The Norwegian medical handbook recommends that almost everyone with long-lasting, complex pain in need of treatment receives a variant of individually adapted change, coping and activity-promoting treatments, abbreviated ITEMA. The treatment should be structured and prepared [4].

Sundhed.dk highlights knowledge about pain and new coping strategies as the most important measure, together with physical activity and exercise and a balance between activity and rest [2]. NHI describes that nociplastic pain usually requires an adapted programme that takes lifestyle, mood, activity, work and social circumstances into account [1].

Many municipalities offer courses in coping with chronic pain. With severe loss of function, a multidisciplinary pain centre may be relevant, and waiting times can be long [2]. Common over-the-counter painkillers rarely have a good effect on persistent pain, and medical treatment is assessed by a doctor [2].

Dr.Dropin is a supplement to the GP and other public services. A chiropractor can go through your history, examine muscles and joints and talk with you about how activity can be adapted to your symptoms. You can read more about chiropractic and about psychomotor physiotherapy.

What is nociplastic pain?

NHI uses the term for pain that arises from an altered perception of pain, without clear tissue damage or nerve damage. It is linked to changes in the nervous and immune systems [1].

When is pain considered persistent?

Pain that has lasted more than three months is considered persistent [3][4]. NHI also mentions an interval of three to six months [1].

Can pain continue after an injury has healed?

Yes. Sundhed.dk describes that the pain can continue even though an earlier injury has healed, often in connection with an oversensitive nervous system [2].

Is it common to have persistent pain?

The Norwegian Institute of Public Health reports that between 35 and 55 percent of Norwegian adults have persistent pain in some form [3].

Should I rest when the pain is persistent?

The sources emphasise physical activity and a balance between activity and rest, and NHI describes that inactivity can amplify the pain [1][2].

You can find more articles in the overview of articles. The page about psychomotor physiotherapy describes a service that can be relevant for persistent pain.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Kronisk smerte (Chronic pain). NHI.no. Last updated 21 February 2023. Link

2. Due Bruun K. Behandling af vedvarende eller langvarige smerter. Patienthåndbogen, sundhed.dk. Last updated 13 February 2025. Link

3. Langvarig smerte i Norge (Persistent pain in Norway). Public Health Report, Norwegian Institute of Public Health. Last changed 15 September 2026. Link

4. Borchgrevink PC, Woodhouse A, Trydal H. Langvarig smerte (Persistent pain). Norsk Elektronisk Legehåndbok. Revised 7 March 2025. Link