Bad breath may occur due to upper respiratory tract diseases such as tonsillitis, pharyngitis, tonsil stones and sinusitis, as well as inadequate oral hygiene. ⠀ ⠀ In addition, bacteria present in the mouth, dry mouth that may occur as a result of decreased saliva secretion, nose and sinus tumors, tumors of the oral cavity, tongue, larynx and pharynx may also cause bad odor.⠀