Hello dear and welcome to the medhelp forum. the hard lump on the bottom of occipital could be due to swollen lymph nodes behind the ear and head due to different infections like scalp infection, allergies and cough / cold. Check for anemia, endocrinopathies, electrolyte abnormalities and dehydration, micronutrient deficiencies etc could cause dizziness, headaches, and achy legs. Consult a physician for detailed examination and relevant intervention. MRI brain should also be done to check for any tumors in the brain. Wishing him all the best. Take care.
Thank you very much for your prompt reply. I'm sorry to be a pest but I should have added that the lump doesn't move, is not sore to the touch and is at the right of the cervical spine and bottom edge of occipital. Could that still be as a result of the above answers? He had an Xray this morning and the results go to the doctor in two weeks. At least I got him to agree to that.