Chronic pain can be a consequence of malfunctions in the nervous system in which the nerve cells become hypersensitive.
Conventional painkillers often do not help. However, chronic pain can be treated with non-drug treatments and special medications.
Acute pain is pain that lasts from a few days to weeks, but not more than three months. This corresponds approximately to the period in which the body repairs most tissue injuries, such as a broken bone, a torn ligament or a herniated disc.
Pain that lasts longer than three months is referred to as chronic pain: it persists even though its cause has healed. Pain research assumes that they are often the result of a nervous system that has become hypersensitive.
What is the difference between acute and chronic pain?
Acute pain has an important protective function: if you prick yourself on a thorn or touch a hot hotplate, the immediate pain stimulus causes you to pull your hand back quickly. This protects the body from a major injury. If tissue damage has already occurred, pain provides protection and undisturbed healing – because it hurts to touch the wound or move the injured part of the body, for example.
In contrast, chronic pain usually has no meaningful function. On the contrary, they can cause a variety of problems – for example, they can restrict mobility, disrupt sleep, lead to exhaustion and psychological stress and impair the ability to work. They are also not triggered by acute damage, but by malfunctions of the nervous system or chronic inflammation.
Examples of chronic pain disorders or diseases that can lead to chronic pain are:
Rheumatism (rheumatoid arthritis)
Which types of pain are distinguished?
Pain researchers distinguish between several types of pain:
Nociceptive pain: Pain caused by injury, heat, or tissue or organ disorders such as fractures, colic from kidney stones, or pain resulting from a heart attack. They have an important protective function. With this pain, the pain signals emanate from special pain receptors – the so-called nociceptors. Depending on the cause, the pain can be burning, stabbing or throbbing. Pain in internal organs tends to feel dull, deep or crampy and it is often harder to tell exactly where it hurts.
Pain due to inflammation: They are triggered by inflammatory processes in the immune system – such as infections – and have a similar protective function. In some diseases, however, the immune system is directed against the body’s own cells and causes prolonged inflammation, which can lead to chronic pain. An example of this is rheumatoid arthritis.
Pain due to nerve damage (neuropathic pain): It is caused by irritation or damage to nerve fibres and can have various causes. These include nerve irritation or damage as a result of injury, metabolic disorders or alcohol abuse. Examples of neuropathic pain disorders are sciatica, nerve pain after shingles or pain from nerve damage in diabetes. Neuropathic pain can be shooting or seizure, accompanied by tingling and numbness, and can lead to hypersensitivity. Even small, actually harmless stimuli can cause pain. Neuropathic pain sometimes becomes chronic and independent. This means that they persist even though the injured tissue has recovered.
Pain due to changes in pain processing: Sometimes pain is the result of disturbances in pain processing in the brain. Such pain is often non-specific – there is no known cause, the triggers are manifold. Because such pain has no “reason” and no physiological purpose, it is also called “dysfunctional pain”. Examples of such pain disorders are fibromyalgia syndrome, irritable bowel syndrome or a chronic form of cystitis.
How can chronic pain be treated?
While acute pain can often be treated well with painkillers such as acetylsalicylic acid (ASA), ibuprofen or paracetamol, many people with chronic pain experience little relief. Even strong painkillers such as opioids often do not help. Taking painkillers, however, is associated with various risks and side effects. This applies both to opioids, which can make you physically dependent, and to over-the-counter painkillers such as diclofenac, ibuprofen or paracetamol.
Experts in pain research and medicine agree that chronic pain usually requires different treatments than acute pain. It is important to develop strategies that help to cope better with pain in everyday life. This may not eliminate the pain, but it can alleviate it for some people.
For chronic pain, exercise, relaxation and cognitive behavioural therapy methods of pain management are particularly helpful. They are often combined in a so-called multimodal pain therapy. Sometimes medication can also be useful which influences the effect of messenger substances on the nerve cells (neurotransmitters).