The sporadic sense of smell may be caused by acute rhinitis, sinusitis, nasal polyps and other diseases, it is recommended to consult a doctor in time for examination. 1. Acute rhinitis: Suffering from acute rhinitis may cause the sense of smell to be sporadic, accompanied by nasal itching, nasal dryness, nasal congestion and other undesirable symptoms, nasal secretions will increase, there will be a runny nose, and some patients will also experience discomfort in the throat. 2. Sinusitis: Sinusitis can also cause the sense of smell to be sporadic, patients usually have nasal congestion, runny nose and other symptoms, the nasal cavity will be attached to a large number of purulent secretions, may also cause headache, dizziness and other discomforts, and may lead to loss of the sense of smell in severe cases. 3. Nasal polyps: the sporadic smell may also be the discomfort caused by nasal polyps, can cause nasal congestion, polyp volume is large may affect the breathing, suffering from such diseases may cause facial and head pain, some patients will have throat pain, foreign body sensation and other symptoms. There are many reasons why the sense of smell may be sporadic, so it is important to consult a doctor in a timely manner to diagnose the cause of the disease and choose the appropriate treatment according to the doctor’s advice.