Hit my head at work 4 weeks ago, reported immediately but didn't think necessary to see doctor. Went to nurse about 11 days later because still had bump and dull ache. She ask basic questions, did you loose concouisness, blurry vision, blinding headache, etc..? All, no. But, 4 weeks later some days the bump/area hurts worse than others and I am getting concerned. My head (back of head, to left, bottom of center) still aches. How long should this persist and when do I need to be really concerned? Nurse at work just said come back if it still bothers you. Bit of a vague answer to me.