The crossword solution for the term 'KIND OF PAIN' is 'ROYAL'. Pain can be classified into two categories: acute and chronic. Acute pain is usually short-term and is caused by an injury or illness, while chronic pain is long-term and can be caused by a variety of conditions. ROYAL pain is a type of chronic pain that is caused by a medical condition known as complex regional pain syndrome (CRPS). CRPS is a neurological disorder that causes severe and persistent pain in the affected area. It is often accompanied by other symptoms such as swelling, changes in skin color, and sensitivity to touch.