Why does one get synovitis of the hip?

Doing too much. Tendinitis/bursistis of hip often results of over use/trauma/prolonged sitting and the first thing to do is take it easy/rest a bit. Antiinflammatory meds such as aleve/motrin may help. Physical therapy/gentle stretching/rom exercises. Iontophoresis ultrasounds therapy, topical meds etc..May help quite a bit as well. So, if doing on your own not enough, consult doc for possible injection. Good luc.