When pain no longer follows the usual pattern
A cut heals within days. A sprain, within weeks. Pain normally follows a similar course: it appears to protect injured tissue, then gradually subsides as healing progresses.
For some people, however, it does not go away. Tests may return to normal, the original injury may be long past, yet the pain remains. This can be confusing both for patients and for those around them, and it deserves a more meaningful explanation than "it's all in your head" or "you just have to learn to live with it".
A difference in duration, not intensity
The distinction between acute and chronic pain is not about how much it hurts. It is about how long it lasts. Pain is generally considered chronic when it persists or recurs for more than three months. It may continue even after the original injury has healed, or gradually become less directly related to the problem that first triggered it.
In Switzerland, this is far from uncommon: around 1.5 million people live with chronic pain, according to the Revue Médicale Suisse and University Hospital Zurich (USZ). Back, joint, muscular and digestive pain can present very differently, but some of the mechanisms that contribute to their persistence may overlap.
Why pain persists
Three elements repeatedly appear in what pain physiology has revealed over recent decades.
The first involves the nervous system itself. After intense or prolonged pain, the spinal cord and brain can become more sensitive to pain signals, a phenomenon known as central sensitisation. The nervous system may continue to amplify or maintain pain signals even after the original injury has healed, or when that injury alone no longer fully explains the intensity of the symptoms.
The second involves inflammatory processes. Depending on the situation, they may contribute to ongoing sensitivity in tissues and the nervous system, although their importance varies according to the type of pain and the individual situation.
The third is broader: disrupted sleep, prolonged stress, anxiety, and gradually reducing movement because of fear of pain. These factors do not invent the pain, but they can contribute to maintaining it. This is part of what pain centres, including major Swiss university hospitals, describe through a biopsychosocial approach: chronic pain is often influenced by several interacting factors.
Normal tests, real pain
A standard MRI or blood test does not directly measure how the nervous system processes and modulates pain signals. Reassuring test results can therefore coexist with persistent and very real pain.
This gap between reassuring results on paper and the reality of pain in everyday life is a major source of frustration for people who have lived with chronic pain for months, sometimes years, without receiving an explanation that truly makes sense to them.
Looking beyond the symptom
In my practice, I do not only look at where it hurts. I look at why it continues to hurt, which, when pain has been present for a long time, is rarely a question with a single answer. Nutrition, sleep, stress levels, certain inflammatory processes, mobility and compensatory muscle tension may all, depending on the situation, be factors worth considering.
Looking for the factors that may be maintaining pain, rather than focusing only on treating the symptom in the moment, is part of an integrative approach. It is not a promise of a cure. It is a different way of asking the questions.
When to seek help
Pain that persists for several months, particularly when it limits everyday activities, deserves a thorough assessment, even if the first tests were reassuring. Early management can help identify factors that favour the persistence of pain and provide an opportunity to address them before some of these mechanisms become more established.
Sources and further reading
Revue Médicale Suisse, "Prévenir la douleur chronique : le rôle clé du médecin de premier recours" (special issue on chronic pain, June 2026), on preventing the development of chronic pain and the biopsychosocial factors involved.
USZ, Acute and chronic pain, a Swiss institutional resource on the mechanisms of chronic pain.
These resources provide further information on the mechanisms discussed above.
Frequently asked questions
How long does pain have to last before it is considered chronic?
In practice, pain lasting more than three months is generally considered chronic, which is the threshold commonly used in the medical literature.
Is chronic pain "all in the head"?
No. Pain is a real experience. Stress and emotional state can influence how the nervous system processes pain, but this does not mean that the pain is imagined or voluntary.
Can chronic pain improve?
Yes, chronic pain can change and improve. The possibilities depend on factors including its cause, duration, the mechanisms involved and the individual's situation. Identifying factors that contribute to maintaining the pain can form part of its management.
Do I need a precise diagnosis before I can start doing something about the pain?
Not always. A medical assessment remains important to identify causes that require specific treatment. However, the absence of a single diagnosis that fully explains the pain does not prevent work on factors that may contribute to maintaining it, such as sleep, movement, stress or certain lifestyle habits.
What is happening in your case?
This article describes general mechanisms. What is maintaining a particular pain, your pain, is a different question, and one that deserves a real conversation rather than a generic answer.