Hi i've had bad breath for a while now. i always have a residue on the back of my tounge like mucus and i'm always having to blow my nose.

Bad breath: Impossible to answer without a complete history.Mucus;cold can be a sign of post nasal drip-this can cause bad breath. Other causes can be systemic disease, your diet, from medications. One big cause can be from mouth - periodontal(gum)disease, bad teeth, lesions, and the tongue. You should be checked by your dentist and md depending on history.Dentist who knows about bad breath or oral medicine.

Bad breath: Has your PCP evaluated tonsils/adenoids & for post-nasal drip. Have you been evaluated for GERD or diabetes. When was your last dental check-up. Do you brush twice daily for 2 full minutes. Do you floss daily. Do you brush your tongue. Do you eat highly aromatic foods. Has your diet/medications/supplements changed. Has an ENT evaluated your sinuses. Time for some examinations.