It is not possible to say what these lumps are just on the basis of your description. It is possible that they are entirely natural and do not require any treatment at all. The skull is not usually perfectly round and smooth, so to some extent, lumps and protrusions are normal. In addition, past injuries, particularly those suffered in childhood, leave many people with permanent lumps on their heads. Since you haven't mentioned any pain or change in the lumps on your scalp, it is likely that they are due to one of these reasons. Another relatively benign possibility is a sebaceous cyst or a minor infection of a few hair follicles. If there is an infection, the lumps are likely to be painful, but unless they seem persistent or the pain is too much to bear, no treatment is necessary. Sebaceous cysts are also quite harmless and do not require treatment. Such cysts are rather common on the scalp, and usually disappear on their own. Only if a cyst becomes infected or continues to grow does it need to be treated. There are however some rare conditions, such as sebaceous gland carcinoma, that may result in lumps on the scalp, so you should get your doctor to examine you.
answered by G R