Hello, As per my clinical experience, an external visible bump on side of head usually indicate soft tissue lesion as lipoma or bony growth as osteoma most likely. The consistency of the lump by palpation through physical examination is of paramount importance to differentiate among two of the common conditions. The dizziness and migraine do not correlate with the said lump and it can be related to neurologic conditions of altered neurotransmitters or else. It would be advisable to take a photo shot of the lump and share it during follow up discussion for further discussion and guidelines. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Bhagyesh V. Patel, General Surgeon