The runny nose is mucus secreted by mucous glands on the mucous membranes of the nose and sinuses.
Under normal circumstances, in order to regulate the air humidity in the respiratory tract and protect the respiratory tract, the glands with secretory function on the mucous membrane of the nose and sinuses will continuously secrete a transparent, thin mucus, which is also known as snot. These snot with the swing of the nasal cilia, transported to the back of the nasopharynx and pharynx, with the swallowing action into the stomach, usually do not feel the nasal cavity with snot.
When a cold or suffering from rhinitis, sinusitis, the nasal mucosa inflammatory reaction, resulting in increased secretion, the inflammation of the nasal mucosa will also make the swing of the nasal cilia weakened, so that the symptoms of a runny nose. If there is a secondary bacterial infection, the symptom of a runny yellow nose can occur.
When a person cries, part of the tears produced by the lacrimal gland enters the nasal cavity through the nasolacrimal duct, so the symptom of runny nose can also occur when crying.
If abnormal nasal discharge occurs, it is recommended to go to the hospital for a clear diagnosis and follow the doctor’s instructions.