for the past week Iam feeling a slight pressure in my head, it feels like the beginning of headache , but it is not a headache.I can feel it more on a supine position, I don t have anxiety , eat well, and I am active, I am not overweight . the only medication I take is the generic version of Zocor. 40mg. sometimes I feel it in my left size of skull . sometimes in the back, sometimes on the top of my head. please explain thanks. Jerry