Swallowing saliva with a fishy odor in the throat may be caused by chronic sinusitis, purulent tonsillitis and other diseases. 1. Chronic sinusitis: chronic sinusitis, there may be pharyngeal saliva throat with a fishy odor, mainly due to the increase of purulent secretions in the nasal cavity, backflow into the pharynx will appear odor, the patient is usually accompanied by nasal congestion, pus flow, loss of smell and other symptoms, and some patients will have a headache. 2. purulent tonsillitis: purulent tonsillitis will cause pharyngeal saliva throat has a fishy smell, this kind of disease will make the tonsils inflammation pus secretion, cause a large number of bacterial growth, triggered by the oral cavity odor, the patient will usually be accompanied by fever, there will be chills, malaise and other adverse symptoms, the pharynx will be obvious pain, aggravated when swallowing. This kind of situation requires timely medical treatment, examination and clear diagnosis.