Hello and welcome to HCM, Raised ESR level is not a disease but an indication of an underlying chronic disorder. Associated headache raises possibility of temporal arteritis. Temporal arteritis is characterized by inflammation of vessel wall of temporal artery. Definitive diagnosis of temporal arteritis can be made after biopsy of the vessel wall. However, the biopsy is negative for evidence of temporal arteritis. Ulcerative colitis is a chronic autoimmune disorder which can also cause raised ESR. ESR responds to treatment of underlying disease. Thus, treatment for ulcerative colitis will improve the ESR levels. Thanks and take care Dr Shailja P Wahal