Why Pain Can Continue After Healing

For many people with persistent pain, one experience is especially frustrating: being told the injury has healed, or the scan looks normal, while still hurting every day.

It can feel like no one believes you, or like something has been missed. It raises hard questions. If nothing is wrong, why do I still hurt? Does this mean it is in my head? Will it ever get better?

These questions are completely understandable, and the answer matters. The short version is this: pain can absolutely continue after tissues have healed, and that does not mean it is imagined, exaggerated, or permanent. Understanding why is one of the most important steps in managing it.

How pain normally works

Pain is not simply an electrical signal travelling from a sore area to the brain. It is, above all, a complex personal sensory and emotional experience influenced by interacting somatic, psychological and social factors.

When tissue is damaged, specialised sensory nerve endings called nociceptors detect and encode noxious—that is, tissue-damaging—stimuli. This information travels through the nervous system to the brain, where it is processed alongside other information relating to the person’s circumstances, previous experiences, expectations, stress, emotions and current health. The output is a pain experience.

Nociception is the signalling to the organism of tissue damage. Nociception and pain are separate but related phenomena. Activity in nociceptive pathways does not always result in pain. Although pain can occur without clear evidence of ongoing tissue damage, there is no evidence that it can occur without activation, in some form, of those pathways. Pain is therefore best understood as a whole-person experience arising through complex and distributed processes—not as a direct reflection of tissue damage.

A note on terminology

This explanation adopts the position that nociception is necessary, but not sufficient, for pain. This position goes further than the current International Association for the Study of Pain (IASP) formulation, which states that pain and nociception are different phenomena and that pain cannot be inferred solely from activity in sensory neurons.

What sensitisation means

When pain persists without underlying disease processes or ongoing tissue damage, the nervous system has become more sensitive to all stimuli - both noxious and non-noxious. This is called sensitisation of nociception.

Picture a volume dial. Normally it is set at a level that allows comfortable listening. In some cases of prolonged pain, that “volume dial” of pain intensity can get turned up, so that signals that would usually be quiet become loud. Events that would not normally hurt begin to do so. This sensitisation happens in two ways:

1. Peripheral sensitisation of nociception means that nerves in and around a previously damaged area become more easily triggered, firing in response to normal movement, touch or changes in local temperature.

2. Central sensitisation of nociception means that pathways in the spinal cord and brain themselves have become more reactive. 

When sensitisation happens, pain can spread beyond the original site, persist after healing, be set off by light touch or movement, and vary in intensity unpredictably.

Why a normal scan does not mean no pain

A normal scan does not mean no pain. Scans such as MRIs and X-rays can show only structure: bones, discs, joints, some soft tissue. They do not show pain or its apparent source.

By contrast, many people have significant findings on medical imaging, such as bulging discs or joint wear, but with no pain at all. And many people with severe pain have scans that look completely normal. Scans are a useful tool to identify potentially treatable pathology, but they are only one piece of a much larger picture.

Why the brain maintains a pain experience

Once sensitised, nociceptive pathways including the brain can keep maintaining pain, even without ongoing tissue damage. How this actually happens is unknown.

This is not a matter of choice, a weakness, or a character flaw. It is normal biology that has evolved over time.

Several factors can complicate this process:

• Fear of movement

• Stress and anxiety

• Poor sleep

• Low mood

• Inactivity

This is not imaginary or "all in your head”

This point is very important to understand, so it is worth being clear. Saying that pain involves the brain, or that the nervous system has become sensitised, does not mean that the pain is imaginary or “psychological” or any less real.

Pain produced by a sensitised nervous system hurts every bit as much as pain arising from a fresh injury. It disrupts sleep, function and life just as much, and deserves exactly the same attention, compassion and care. Understanding sensitisation of nociception explains the otherwise inexplicable situation, and points toward strategies that genuinely help.

What can help

Because this kind of pain is driven more by nervous system sensitivity than by ongoing damage, the most useful strategies work with the nervous system rather than focusing only on the sore area.

• Learning how pain is generated can reduce fear of the unknown and lower the person’s sense of threat to their being.

• Gentle, graded movement, within an envelope of tolerated pain, can show the person that movement is safe.

• Pacing activity, to avoid boom-and-bust cycles.

• Managing psychological stress and low mood, which lightens the “other information” load on the person.

• Improving sleep, which directly improves pain control.

• Psychological strategies such as cognitive behavioural approaches, which target unhelpful thought patterns.

None of these strategies are quick fixes. But together, over time, they can make a real difference to pain intensity, function and quality of life.

REFLECTION

KEY TAKEAWAY

Pain can continue after tissues heal because the nervous system can become sensitised, more reactive, and quicker to maintain pain. This is a real biological process, not imagination or personal weakness, and strategies designed to calm the sensitised nervous system can genuinely help.

Expert review and contribution: Dr Milton Cohen and Dr John Quintner