Frequent runny nose is considered to be caused by chronic rhinitis, allergic rhinitis, nasal malignancy, sinusitis and other causes. It is recommended to go to the ear, nose and throat department of the hospital to identify the cause of the disease and further treatment. 1. Chronic rhinitis: after the nasal mucosa is infected by bacteria, viruses and other pathogenic microorganisms, pathological changes such as congestion, edema and increased mucosal exudate can occur, which can lead to frequent runny nose. 2. Allergic rhinitis: Allergic rhinitis is a disease in which the nasal mucosa undergoes an allergic reaction due to the exposure of the body to allergic substances. After the nasal mucous membrane undergoes obvious allergic reaction, it will lead to a series of changes such as increased activity of parasympathetic nerves, proliferation of glands, exuberant secretion and increased nerve sensitivity, so it will lead to frequent runny nose. 3. Nasal malignant tumor: Nasal malignant tumor in the early stage usually does not have symptoms of runny nose, to the middle and late stage due to the destruction of the nasal mucosa, there will be nosebleed, runny nose and other symptoms. 4. Sinusitis: Sinusitis due to inflammation of the tissue can be damaged to the nasal mucosa, resulting in nasal mucosa congestion and swelling, swelling and secretion accumulation, so often runny nose symptoms. If often runny nose need to go to the hospital in time to check the specific causes and treatment, so as not to delay the condition.