In children with good oral hygiene, smelly breath that persists throughout the day is most often the result of mouth-breathing, which dries out the mouth and allows the bacteria to grow. Saliva cleanses and rids the mouth of bacteria, so anything that causes dry mouth may cause bad breath as well.
Children who consistently breathe through their mouths might have colds, sinus infections, allergies, or enlarged tonsils or adenoids blocking the nasal passages, so a visit to the pediatrician is in order.
Thumbsucking or sucking on a blanket can also dry out the mouth. Dry mouth can also be caused by certain medications, so be sure to mention any medications and/or supplements your child is taking when you visit the pediatrician.
For most children, bad breath is not associated with any serious conditions. However, here is a list of some uncommon, but telltale, odors.
Three-year-olds often stuff items in their noses, and then forget about them. When my son Kevin was three, he put five peas up his nose before anyone found out! Watch for the combination of smelly breath and a smelly, yellow nasal discharge — especially from one nostril. You and I might not think of stuffing peas up our noses, but three-year-olds think outside the box!
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