Chronic pain differs from acute pain in that it no longer serves a direct function. While acute pain is the body’s alarm system – for example, when you burn yourself – chronic pain often continues even after an injury or illness has been treated. Pain is classified as chronic when it lasts for more than 3–6 months. Many people find relief, but the pain often becomes a constant part of everyday life.

About one in five Danes lives with chronic pain, and around one in four experiences daily pain. Women are affected more often than men. For most – about 60% – the pain originates from muscles, bones, or joints, while headaches and migraines account for around 10%.

The three main types of chronic pain

Nociceptive pain arises in muscles, joints, or organs, for example with osteoarthritis, fibromyalgia, or injuries. The cause may be clear, such as with a herniated disc or spinal misalignment, but often there is no obvious explanation – especially for pain in the neck, shoulders, or buttocks.

Neuropathic pain stems from damage to the nervous system, for example after surgery, diabetes, shingles, or multiple sclerosis. It can occur immediately or months later, and the cause can be difficult to identify.

Central sensitization (nociplastic pain) is caused by increased sensitivity in the nervous system without any current injury. Persistent pain signals can change the brain’s perception, making one more sensitive, and the pain may spread. Fibromyalgia and whiplash are often associated with sensitization.

Chronic pain has a major impact on daily life. Many experience memory and concentration problems, poor sleep, fatigue, and an increased risk of depression or anxiety. Long-term pain can be difficult to understand because it does not always mean something is physically wrong – it can be due to an overreactive nervous system. It is therefore important to pay attention to changes in the location and nature of the pain.