Causes of Chronic Pain

Where Does the Pain Come From?

Pain Basics
Pain is an unpleasant sensation that occurs after an injury or illness. Pain is actually a good thing. It is there to alert us that something is wrong. Without pain we may not know that we have been injured. Feeling the pain is our signal to go out and try to fix the injury.

Pain receptors are found all over the body, on your skin, bones, muscles, ligaments, joints and even blood vessels. When you become injured the receptors work like gates, allowing messages to pass from one nerve cell to another. They do this by using chemicals called neurotransmitters.

What’s Different about Chronic Pain?
When you become injured or develop an illness pain signals are sent to your brain. Usually these signals stop when your illness or injury has healed. For instance, if you fracture your big toe you would be expected to have pain in your big toe. After the fracture has healed the pain should stop. But sometimes the pain sticks around. With chronic pain the signals do not shut off when they are supposed to. The pain can persist for months or years.

What kinds of illnesses cause chronic pain?
Many medical conditions can be related to chronic pain. These conditions include:

• Diabetes
• Arthritis
• Bursitis
• Chronic fatigue syndrome
• Tendonitis
• Fibromyalgia
• Disc herniations
• Fractures
• Neuropathy
• Whiplash
• Myofascial pain syndrome
• Shingles
• Sciatica
• Temporomandibular joint disorder (TMJ)

In some cases the original cause of the pain can’t be identified. The standard tests and examinations may not reveal a source for your pain.

Why don’t the pain signals work?
No one knows exactly why the pain signals don’t work properly for people with chronic pain. Recent research suggests that people with chronic pain may have lower than normal levels of endorphins in their spinal fluid. Research should result in a better understanding of chronic pain in the near future.

_Sources:

Tollison et alPractical Pain Management, 3rd Edition

Robinson JP “Chronic pain” Physical Medicine Rehabilitation Clinics of North America 2007 Nov;18(4):761-83, vii.

"Pain: Hope Through Research," NINDS. Publication date December 2001. NIH Publication No. 01-2406