I have a small lump on the back of my head on the left side. it is very sore, even without anything touching it, it aches. have a sore head and dizzy.

See a doctor: Any painful lump deserves to be checked. It could be a skin cyst, an ingrown hair, or an area of inflammation of the skull bone or overlaying skin. I just had a 21 year old female who had a non-cancerous growth in the skull bone that was causing her pain. One of the cancer warning signs: Lumps or thickened areas in the breast, testicles, or elsewhere. At your age you R unlikely to have cancer.