What can u do for tendentis?

Rest: Stretching gently, cool compresses.

Tendinitis : Rest, ice. On some occasions steroid injections but has a side effect of tendon rupture.

Depends on location: Acute tendonitis (that started recently) can be treated with icing (15 minutes at a time) and relative rest of an area (with a splint or brace). See your doctor to make sure that this is the proper diagnosis, and to see if a course of physical therapy will help (it if doesn't go away on its own after a couple of weeks).