My ferritin level is 6 but my hct/hgb are normal. can this ferritin level cause symptoms? what causes low ferritin?

U R iron deficient: Probably. You'll start feeling tired before you become anemic as the iron that your cells need for metabolism are deficient. You need to find out why you are iron deficient. If it's pregnancies, your monthly loss, or an ill-advised vegetarian lifestyle, correct it. If not, ask your physician how to identify possible blood loss.