###Human: A foul smell comes out of my nose. What could it be? ###Assistant: Hi. Foul smell is formed by bacteria. So, it is seen in conditions where they are residing for a long time. Normally our nose and throat have commensals and they get washed away by our normal secretions of the nose and throat. Bad smell in nose is seen in conditions like, atrophic rhinitis and pharyngeal web or diverticulum. Atrophic rhinitis, in which it smells bad. After some time, the patient does not get bad smell and only the people around get it. It is a nasal disease and can be diagnosed by examining nose. Pharyngeal web or diverticulum is a condition in which a small pouch is formed from pharynx, away from normal tract. So, whatever you eat, a part of it does not go to the stomach below and escapes into the pouch. It stays there for some time and automatically comes back in pharynx and goes stomach. In this condition, due to retention of food bad smell is produced. For further information consult an ENT otolaryngologist online -->