- An increased sensitivity to feeling pain and an extreme response to pain. Hyperalgesia may occur when there is damage to the nerves or chemical changes to the nerve pathways involved in sensing pain. This may be caused by tissue injury or inflammation or by taking certain drugs, such as opioids, for chronic pain. People with hyperalgesia tend to feel extreme pain even though an injury or medical condition has not gotten worse. This pain may get worse over time, and it may extend to other areas of the body. It may also become a new or different type of pain than the original pain.