Medical professionals categorize pain as either acute or chronic. Acute pain is your nervous system’s way of alerting you to an injury or other damage to your body’s tissues. Acute pain gets your attention so that you’ll take care of yourself fast. In fact, the word acute comes from the Latin word for needle, and if you’ve ever stepped on a needle, you’ll agree that it’s a good representation of acute pain. Acute pain usually goes away as the injury heals, although it may return for short periods.
Chronic pain is persistent pain. The word chronic comes from the Greek word for time. In medical terms, pain is chronic when it lasts three months or more when pain becomes chronic, your body’s pain signals keep firing for weeks, months, or years, even though the damage that set them off may have long since healed. The pain may have been caused by an injury, and, for unknown reasons, your body never turned off its pain switch. Or the pain may have an ongoing cause, such as arthritis, cancer, or nerve damage. You also may have multiple causes of chronic pain, which is particularly common for older adults.
One big difference between acute and chronic pain is when you have acute pain, you usually know why it hurts. (Some examples of acute pain are broken bones, kidney stones, and childbirth.) When you have chronic pain, you may have no idea what’s causing the hurting. The bone has healed, the stone has passed, and the baby is now walking and talking, but you still have lingering problems in the areas where the acute pain occurred.
In addition, many people with chronic pain aren’t even aware that an injury ever occurred in the first place. (And, indeed, maybe there was no injury to begin with!) For them, the pain appears to slam in from out of the blue, like a sudden tornado that levels a house. Whether you know the source, chronic pain is a sensation without purpose. It has no biological function, and its usefulness as a warning system has long since passed or never existed. Ironically, while chronic pain has no purpose, it’s still often difficult to treat. The medical term for this type of pain is treatment resistant pain. Experts describe chronic pain this way: It persists, resists, and insists: It persists beyond the expected healing time, resists interventions (treatments), and it also insists upon being recognized.