The sensation of pain is a neurological component developed as an evolutionary construct to alert humans to injuries. Once the injury is healed, the pain goes away.
Chronic pain, however, is pain that goes on for a long period of time -- sometimes for no discernable reason, although usually as a continuation of an initial issue. Instead of letting your body return to normal, your nerves send pain signals for months or years. Here are a few common causes of chronic pain.
Injury
The easiest way to consider what causes chronic pain is to think about what causes pain, particularly extremely intense pain. Trauma and severe injuries often lead to chronic pain. Sprains, strains, and pulled muscles can all begin as acute pain (a rapid onset), but develop into chronic pain (continuous presence). Chronic back pain is one of the most common types of chronic pain. This can be a result of pulled muscles, occupational hazards (such as a job involving frequent heavy lifting), athletic incidents, or a host of other accidents.
The nerves can also suffer damage. Neuropathy is a side effect of some diseases, such as diabetes. The pathways that carry sensations can be damaged, although neuropathy can affect different types of nerves. Peripheral neuropathy, for example, is characterized by a frequent tingling or numbness; the muscles may grow weak and there may be a prickling sensation.
Pain Disorders
There are many disorders characterized by different types of pain. Arthritis, an umbrella term for a plethora of joint diseases and joint pain, is a leading pain disorder. The joints may ache from a metabolic issue, degeneration, infection, immune abnormalities, and many other reasons. While some arthritides may periodically seem to get better, they generally get worse again and can remain problematic for long stretches of time.
Fibromyalgia is a disorder in which muscles all over the body are in discomfort or pain almost all the time. The exact cause of this is still under research, but it is believed that it is rooted in a misconception of the brain’s response and/or processing of pain signals.
Headaches
Headaches are a leading chronic pain complaint. There are several different types of headaches; they may arise as a result of stress, tension, or fatigued ocular muscles. Migraine headaches are thought to be triggered by the nervous system, while cluster headaches are the result of blood vessels that have become enlarged. Many people who suffer from headaches, particularly migraines -- which can be disabling -- find it difficult to get out of bed on days when they have a headache. For some people, that’s nearly every day.
Chronic Conditions
Other medical issues that are not necessarily based on painful problems can lead to chronic pain, particularly when the chronic pain in question has no discernable cause or is the result of an injury that should have healed long ago.
Chronic fatigue syndrome is a disease in which the individual essentially feels exhausted for long stretches of time. They may experience flu-like symptoms that go on for weeks at a time. Pain often accompanies chronic fatigue syndrome. Other diseases that cause chronic pain may be more systemic than global. Inflammatory bowel diseases cause chronic abdominal pain. During periods when the disease is “triggered,” it can be difficult to perform everyday tasks because of the intensity.