Hello there. I can understand your concern. Do you have any other issue like fever? Chills? Burning sensation while passing urine? Raised ESR indicates some on going infection or other inflammatory process. Your ESR alone is raised but WBC are well under normal limits so infection is un likely. It usually comes down by itself after a few days. I do not understand the rationale of doing a blood test for headache. Take a pain killer like paracetamol for now and consult a general physician in person if it still persists . Best regards. Dr. Anil kumar jain.