Health and Pain Mind

Pain may be acute or chronic. Acute pain begins suddenly and usually does not last long. Chronic pain lasts for weeks or months. Usually, pain is considered chronic if it does one of the following:

• Lasts for more than 1 month longer than expected based on the illness or injury
• Recurs off and on for months or years
• Is associated with a chronic disorder (such as cancer, arthritis, diabetes, or fibromyalgia) or an injury that does not heal

When severe, acute pain may cause anxiety, a rapid heart rate, an increased breathing rate, elevated blood pressure, sweating, and dilated pupils. Usually, chronic pain does not have these effects, but it may result in other problems, such as depression, disturbed sleep, decreased energy, a poor appetite, weight loss, decreased sex drive, and loss of interest in activities.

During treatment for chronic pain, many people experience a brief, often severe flare-up of pain. It is called breakthrough pain because it breaks through in spite of regularly scheduled pain treatment. Typically, breakthrough pain begins suddenly, lasts up to 1 hour, and feels much like the original chronic pain except it is more severe. Breakthrough pain may differ from person to person and is often unpredictable.

Chronic pain can make the nervous system more sensitive to pain. For example, chronic pain repeatedly stimulates the nerve fibers and cells that detect, send, and receive pain signals. Repeated stimulation can change the structure of nerve fibers and cells or make them more active and can thus increase pain transmission to the spinal cord and brain. As a result, pain may result from stimulation that might not ordinarily be painful, or painful stimuli may be felt as more severe.

When pain occurs repeatedly, people may anticipate it by becoming fearful and anxious. These emotions can stimulate the body to produce substances that make pain feel more intense. An example is prostaglandins, which make nerve cells more likely to respond to pain signals. Fear and anxiety can also reduce the production of substances that reduce the sensitivity of nerve cells to pain. An example is endorphins, the body’s natural pain relievers. Fatigue can have the same effects on pain as fear and anxiety.

These changes in pain sensitivity partly account for pain that persists after its cause resolves and for pain that feels more severe than expected.