There is a bloody odor but no blood in the nose, which is considered to be related to nasal foreign body, sinusitis, nasal polyp, nasopharyngeal carcinoma and so on. 1. Nasal foreign body: when the nasal cavity into the insects, peanuts and other foreign objects, can be due to foreign body fermentation and damage to the nasal mucosa and appear in the nose with a bloody odor but no blood phenomenon. 2. Sinusitis: the disease is related to the neighboring organ infection lesions, trauma, gastroesophageal reflux disease, etc. The disease can cause the patient to have fever, loss of appetite, nasal congestion, pus flow, loss of smell and other symptoms. When the disease causes some patients with reduced sense of smell, sinus mucosal damage, can be manifested as a bloody odor in the nose but no blood. 3. Nasal polyps: the disease is related to pathogenic microbial infections and allergic reactions. Nasal congestion, increased nasal secretion, decreased or lost sense of smell are the symptoms of the disease, and some patients can also have the phenomenon of bloody odor but no blood in the nose due to increased secretion and concurrent infection caused by nasal polyps. 4. Nasopharyngeal cancer: the disease is related to EBV infection, heredity, etc. Patients may have tinnitus, hearing loss, nasal congestion, headache, diplopia and other symptoms. The disease can also cause a small number of patients to have bloody smell but no blood in the nose, which is mainly related to the stimulation or damage of local tissues by cancer cells. It is recommended that people who have a bloody odor but no blood in the nose should consult a doctor for examination to check the nasal cavity and other diseases. Daily attention should be paid to adjusting the state of mind, avoiding excessive tension, anxiety, etc., and attention should also be paid to strengthening nasal care.