Mechanisms of Pain
Just as there are different types of arthritis, there are also different types of pain. The pain you experience can come from various areas of the musculoskeletal system and involve different types of information processing. To learn more about the basics of the nervous system and pain, see Understanding Pain.
This is the normal mechanism that the body uses to process pain day to day. Nociceptive pain occurs when tiny nerves (nociceptors) that run on the surface of organs, muscles, joints and throughout the body are stimulated. These messages are carried by nerves to the brain. For example, when you bang your elbow, you feel nociceptive pain.
- Mechanical Pain. Nociceptive pain that happens with stretch or pressure in and around joints is called mechanical pain. Osteoarthritis, low back disorders and tendinitis are common examples of mechanical pain.
- Inflammatory Pain. Inflammation is an essential process that helps the body respond to and heal an injury. But it also activates nerves and causes pain. When joints are inflamed, damage to bone, muscles and cartilage (the slick surface between bones of the joints) can occur. Examples of inflammatory arthritis are rheumatoid arthritis, psoriatic arthritis, lupus, gout and ankylosing spondylitis.
Neuropathic pain happens when there’s too much or persistent pressure on nerves or they are damaged. It’s often described as burning, tingling, shooting, stinging or as “pins and needles.” Some people may describe a stabbing, piercing, cutting or drilling pain. An example of this type of pain is sciatic pain due to irritation of the sciatic nerve by a disc or bone spur. The pain starts at an area of the spine in the lower back and can run across the hip and buttock and down the leg.
Centralized pain was first used to describe pain that happens when the central nervous system (brain, brainstem, spinal cord) is damaged. It now is used to describe any pain that happens when the central nervous system doesn’t work properly and amplifies or increases the volume of pain. Other terms used to describe this condition include “central sensitization,” “central amplification” and “central pain syndrome.” Several common conditions, such as fibromyalgia, irritable bowel syndrome and temporomandibular joint disorder are examples. Arthritis joint pain can also become centralized in some people, especially if it is long-lasting.
Psychogenic pain is an older term for what happens when emotions cause pain in the body, make existing pain worse or make it last longer. As doctors learn more about how the central nervous system works, fewer types of pain are put in this category. For example, fibromyalgia was once considered psychogenic, but new discoveries have shown problems with pain processing in fibromyalgia. Headache, muscle pain and low back pain are commonly influenced by your emotions.
Sometimes, people living with arthritis and related conditions can experience different types of pain at the same time. That’s why it’s important to work with your doctor to develop the best pain management plan for you, which may include many different strategies.