<s>[INST] Hello, Tuesday 29th July I hit my head and was unconscious for about 2/3 minutes... Managed to get a horrible cold the next day and a week later I ve come up with a hard lump on my mastoid process (slightly above my earlobe) and the area just above the lump is tender. [/INST] Welcome to Chat Doctor .1. The possible cause of the lump could be subbed cutaneous / intro muscular hematoma. 2. Loss of consciousness is serious issue, in your case I would have asked for a CT best to find out ant intracranial involvement, bony injury.3. For symptomatic you can use the painkiller cream and there are thrombolytic superficial applicable creams - but needs to get proscribed from your GP.4. See for a day or two - if resolving then fine, If not then you have to get an appointment and get the needful tests and treatment done. Hope it helps you. Wish you a good health. Anything to ask ? Do not hesitate. Thank you. </s>