Runny nose when you don’t have a cold is mostly a disease of the nose itself, consider allergic rhinitis due to allergic factors. Such patients sneeze and runny nose whenever they encounter irritating gases or hot or cold air. Generally, clear nasal discharge, if combined with yellow nasal discharge, bacterial infection may occur and oral antibiotic treatment is required. If the runny nose is caused by simple allergic rhinitis, it is recommended to wear a mask and avoid contact with irritating foreign substances. If the symptoms of allergic rhinitis are heavy, you can take anti-allergic drugs such as loratadine for treatment, as well as nasal rinsing to keep the nasal mucosa clean and moist. If there is blood in the nose, it is recommended to go to ENT department for examination to exclude nasopharyngeal cancer.