1. Surprising Reasons You're in Pain Slideshow Pictures
2. Slideshow: Good and Bad Exercises for Low Back Pain
3. Take the Pain Quiz!

In this Article

• Introduction to chronic pain
• The A to Z of pain
• How is pain diagnosed?
• How is pain treated?
• Pain management
• What is the role of age and gender in pain?
• A pain primer: what do we know about pain?
• What is the future of pain research?
• Appendix
• Spine basics: the vertebrae, discs and spinal cord
• The nervous system
• Phantom pain: how does the brain feel?
• Chili peppers, capsaicin and pain
• Marijuana for pain treatment
• Nerve blocks for pain treatment
• Where can I get more information about pain?
• Patient Comments: Chronic Pain - Marijuana and Pain
• Patient Comments: Chronic Pain - Management
• Patient Comments: Chronic Pain - Diagnosis
• Patient Comments: Chronic Pain - Effective Treatments
• Find a local Pain Management Physician in your town
• Chronic Pain Index

There is no way to tell how much pain a person has. No test can measure the intensity of pain, no imaging device can show pain, and no instrument can locate pain precisely. Sometimes, as in the case of headaches, physicians find that the best aid to diagnosis is the patient's own description of the type, duration, and location of pain. Defining pain as sharp or dull, constant or intermittent, burning or aching may give the best clues to the cause of pain. These descriptions are part of what is called the pain history, taken by the physician during the preliminary examination of a patient with pain.

Physicians, however, do have a number of technologies they use to find the cause of pain. Primarily these include:

• Electrodiagnostic procedures include electromyography (EMG), nerve conduction studies, and evoked potential (EP) studies. Information from EMG can help physicians tell precisely which muscles or nerves are affected by weakness or pain. Thin needles are inserted in muscles and a physician can see or listen to electrical signals displayed on an EMG machine. With nerve conduction studies the doctor uses two sets of electrodes (similar to those used during an electrocardiogram) that are placed on the skin over the muscles. The first set gives the patient a mild shock that stimulates the nerve that runs to that muscle. The second set of electrodes is used to make a recording of the nerve's electrical signals, and from this information the doctor can determine if there is nerve damage. EP tests also involve two sets of electrodes -- one set for stimulating a nerve (these electrodes are attached to a limb) and another set on the scalp for recording the speed of nerve signal transmission to the brain.
• Imaging, especially magnetic resonance imaging or MRI, provides physicians with pictures of the body's structures and tissues. MRI uses magnetic fields and radio waves to differentiate between healthy and diseased tissue.
• A neurological examination in which the physician tests movement, reflexes, sensation, balance, and coordination.
• X-rays produce pictures of the body's structures, such as bones and joints.