Nose old smell rotten smell, may be the nasal cavity foreign body secondary bacterial infection, atrophic rhinitis, nasal tumor and other factors. 1. Nasal foreign body: Nasal foreign body, erosion or secondary bacterial infection, purulent secretion increase, produce rotten smell, will feel the nose old smell rotten odor, may also be accompanied by pain in the nose, swelling and other symptoms. 2. Chronic sinusitis: it may be caused by infection, allergy and other factors, which will lead to the accumulation of purulent secretions in the sinuses, which will produce a foul odor, and may be accompanied by nosebleed, nasal congestion, olfactory impairment, dizziness, headache and other symptoms. 3. Nasal tumor: a malignant lesion, when there is a malignant tumor in the nasal cavity, there may be ulceration and erosion, etc. The erosion and necrosis of the tissue will cause a special smell, and the nose often smells rotten, which may be accompanied by nosebleeds and other abnormal manifestations. The nose always smells rotten odor, it is recommended to actively seek medical examination to clarify the cause of the disease, to avoid delaying the condition.