Bad breath problems. please help! who do i see?

Start w Dentist. : If problem is not dental - see physician. Bad breath (halitosis) may be caused by smoking, dry mouth, gum infections, poor dental hygiene, certain foods (like garlic, curry, fish oils or onions), sinusitis, post nasal drip, throat infections, infections in the mouth, bronchitis, lactose intolerance, gerd, improperly cleaned dentures, braces ; retainers.