hello, i am 53 yrs old, 5' 0", 132lbs, i have always been healthy and active. recently i have had black stools and very bad nausea. last night i spent the evening on the bathroom floor. i do not vomit, but i shake and mouth waters as if i am going to. prior to that my hair started to thin and now my nails are Very brittle. i do not know if these things are related.