How is your friend doing? I think a doctor is in order. When you say bumps, these are where? Top of head, base of skull? Where? They are muscular in nature? Sometimes we can get a muscle knot that hurts and a massage therapist can do wonders. That would be more if it is by the top of neck, up the bottom of skull. This can definitely give a headache. But something else that comes to mind is tumors. Hope not, but he should get checked. I do want to say that I have various bumps on my head. I just do. Lumpy. But I don't really think about it or realize it unless I have a headache and I'm rubbing my own skull. The skull in general has spots where muscles attach and in general all of that can get tight and give us a headache. Your friend could try putting ice on the bumps. But again, best thing is to see his doctor.
Where are the bumps - front of his head, side, back, neck?
Has he seen a doctor? He really, really needs to. Bumps can be caused by many things, some very serious, some not at all, but please try to get him into a doctor. Any time you have new symptoms and severe pain, it indicates something is wrong.