Why liquid come out through nose?

Nasal discharge, also known as a runny nose, is a common symptom of many respiratory illnesses, including the common cold, flu, and allergies. It occurs when the mucous membranes in the nose become irritated and inflamed, leading to increased production of mucus. This excess mucus can then drain out of the nose.

There are several possible reasons why you might experience liquid coming out of your nose, including:

* Colds and flu: The common cold and flu are both viral infections that can cause inflammation of the nasal passages, leading to a runny nose.

* Allergies: Allergies are a common cause of a runny nose, particularly during allergy season (spring and fall). When you inhale an allergen, such as pollen, dust, or pet dander, your immune system overreacts and produces histamine, which causes inflammation and increased mucus production.

* Sinusitis: Sinusitis is an inflammation of the sinuses, which are air-filled cavities located behind the forehead, nose, and cheeks. Sinusitis can be caused by a bacterial infection or by allergies. When the sinuses become inflamed, they can produce excess mucus, which can drain out of the nose.

* Other conditions: In some cases, a runny nose can be a symptom of other conditions, such as a deviated septum (a misalignment of the nasal septum), a nasal polyp (a noncancerous growth in the nasal passage), or a foreign object in the nose.

If you have a runny nose that persists for more than a week or is accompanied by other symptoms, such as fever, headache, or facial pain, it's important to see a doctor to determine the cause and get appropriate treatment.