8. New answers for pain.(Medical condition overview)

Pain is the chief reason that people seek medical care. And whether it is a tooth, ear, stomach, head, or back that aches, people all want the same thing--relief. Since ancient times, humanity has been preoccupied with finding ways to relieve pain. For thousands of years, our ancestors had only a few substances (mainly alcohol, opium, and the coca and hemp plants) to help make the pain go away.

But modern pharmacology changed all that. Today, dozens of drugs mercifully eliminate, or at least greatly reduce, the pain that comes with all types of ailments. However, their effectiveness for chronic pain is a different matter. Treating chronic pain is tricky; great care and caution must be exercised because of the potential for side effects and addiction associated with pain-relieving drugs.

What Is Pain?

Pain is the body's way of telling us that something is wrong. If we place our hand too close to a fire, we feel pain. When a bone is broken or the skin is cut, if we have inflammation from arthritis, or tense muscles from stress, a signal flashes from nerves in the distressed area to a part of the spinal cord where cells called pain receptors are located. These pain receptors send the signal along different tracks in the spinal cord to the brain, where the message of pain is registered.

Pain evokes emotion. Sudden, short-lived pain can cause anxiety; constant, unrelenting pain can leave us seriously depressed. Because of the emotional aspect of pain, treatment may involve much more than common painkillers, particularly …