<s>[INST] i am 19 years old, I am 5 foot 2, 178 lbs. I have PCOS which I am being treated for as well as hypothyroid. I was sick but the cough has not gone away and now i notice a small lump at the base of my skull. My mother also got sick some time after I did and ended up with pneomonia. [/INST] Hi, Dear,Thanks for your query to Chat Doctor virtual Clinic. I studied your query in all the details put forth by you. I understood your health concerns about the skull lump and pneumonia, as your mother had it recently. Cause of the health problems you queried-AS the history is very short I am unable to comment on the cause of the Lump. Though I could suggest you the following causes for that lump-The lump on back of Skull could be Bug bite(if it is overnight appearance) /Boil or Fur uncle (as you already having air infection with cough)/Or could be incidental epidermis / sebaceous cyst, as it appears to be painless lump. As I don't have any direct photo of the lump / or not many details from you, I would advise you to consult surgeon.Hence, I would advise you to consult ER Surgeon, who would differentiate from other possible causes for the lump in that area. Hope this would resolve your query with full satisfaction. Welcome for any further query in this regard to ME by direct question at Chat Doctor. Write excellent review and hit thanks, to narrate your experience, which would improve my rating for many other visitors to Chat Doctor. Wishing you fast recovery. Have a good day. Chat Doctor. N. Senior Surgical Consultant. M.S. Genl-CVTS </s>