Even severe pain can be controlled very well by combinations of medicines that can be taken by mouth. Pain medicines work best for chronic (long-term) pain if they are used on a regular schedule before the pain becomes severe. It takes more medicine to control severe pain than milder pain, so it’s best to tell your cancer team right away. You’ll want to treat pain when it first starts and regularly after that. If the cause of the pain can be treated, the need for medicine will slowly decrease or disappear as the cause is treated.