What Causes Hot/cold Flushes And Constant Headache?

hi.. i am a 29 yr old male, i have had hot n cold flushes for a couple of weeks now the hot flushes leave me in a pool of sweat.. and the cold flushes make me so cold that showering is the only way i can warm up... i am weak and have a constant headache.. throughout the couple of weeks they have gone away but i just continue getting them back... what is wrong with me???