My left butt pain. i didn't have trauma. i am not athlete. when i massage in i feel pain deep in muscle. i can do all the movements my bach doesn't hurt. what is it? how can it go away?

try local heat for 15-20 mts. a couple of times a day and take acetaminophen. You might have a sprain. If not better in 10-14 days see your MD

Two possibilities. If the pain is in the middle of your buttock cheek or higher, it likely represents a muscle tightness, spasm or strain. If down lower over a bony prominence that you sit on, it could represent ischial bursitis. In both instances, time and avoidance of aggravating factors usually resolves the problem. If persistent beyond 7 days, see a physician.