I have been getting random waves of a metallic smell through my nose. I can t taste it in my mouth only through me nose. After a while my chest starts to feel gurgly (kinda like there s moisture in my airways) and I feel tired and get a headache. It s been happening for about 3 years but I ve never really thought much of it, maybe just that it was a smell in the air. It doesn t always occur, just every now and then and when I get it, it s really strong.