What causes stuffy nose at night?

* Allergies: Allergies are a common cause of stuffy nose at night. When you're allergic to something, your body produces histamine, which causes inflammation and swelling in the nose. This can lead to a stuffy nose, sneezing, and watery eyes.

* Colds and flu: Colds and flu are viral infections that can also cause a stuffy nose. These viruses can irritate the nose and throat, causing inflammation and swelling.

* Sinusitis: Sinusitis is an inflammation of the sinuses, which are located around the nose. Sinusitis can be caused by a variety of things, including allergies, colds, and flu. Symptoms of sinusitis include a stuffy nose, facial pain, and headache.

* Deviated septum: A deviated septum is a condition in which the nasal septum, which is the cartilage that separates the two nostrils, is off-center. This can cause a stuffy nose, especially at night.

* Enlarged adenoids: Adenoids are small glands located at the back of the throat. When adenoids become enlarged, they can block the airway, causing a stuffy nose.

* Pregnancy: Hormonal changes during pregnancy can cause a stuffy nose. This is often called "pregnancy rhinitis."

* Medications: Some medications, such as decongestants and antihistamines, can cause a stuffy nose as a side effect.

* Other medical conditions: A stuffy nose can also be a symptom of other medical conditions, such as asthma, cystic fibrosis, and sleep apnea.