What Causes Unexplained Bruises On The Legs, Thighs And Arms?

hello, im about 19 years of age, female. i got my cbc test results back as normal, though my legs, thighs and arms are covered in unexplained bruises. im oftern tired, scare easy, gums bleed when i brush my teeth, get dizzy very often, also have to watch my blood preassure because it will drop out of no where on me.