<s>[INST] I woke up yesterday with what looked like a bruise but is a discolorization from the back of my left ear down to the middle of the spine.  I also had a terrific headache the entire day.  Can they be related?  And what is the mysterious darkening of the skin that occured overnight?  Should I be worried? [/INST] hello there,Could you tell me if there was any history of head injury or trauma prior to you noticing this bruise? Either ways it is good if you get yourself evaluated with a doctor. The discoloration or bruise that you are referring to may be a small area under your skin that had blood pooling in it. Hope this helps you,Kindly get to a doctor and get examined soon.Dr Arun A </s>