Patients with a very foul-smelling nose exhale need to pay attention to a detailed examination of the nose, and nasal inflammation, foreign bodies, hyperplasia, as follows: 1, nasal inflammation: patients often because of the nasal cavity, sinus thick secretion accumulation factors, resulting in nasal odor, often because of the nasal cavity, sinus inflammatory infectious disease conditions and lead to the above situation. 2, nasal foreign bodies The nasal cavity of the nasal cavity of some patients may appear in the case of foreign bodies, mostly seen in young children, foreign bodies stuffed into the nasal cavity for a longer period of time is prone to secondary infection, resulting in purulent secretions, will also cause the nasal exhalation of gas odor. 3, nasal hyperplasia: some patients may exist in the nasal cavity, sinuses, a variety of benign and malignant hyperplasia, also prone to odor performance.