One blocked nostril can result from allergies, a foreign object, or side sleeping.
Symptoms like sneezing and itchiness often worsen at night due to mucus pooling in the sinuses.
Adults may also encounter nasal blockages from workplace debris, jewelry, or mishandling items like cotton or tissues.

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These objects can cause irritation, bleeding, infection, or difficulty breathing if unnoticed.
The congestion may shift sides, especially at night, due to changes in blood flow while lying down.
Prolonged exposure to allergens can also increase mucus production, further clogging the affected nostril.
Sleeping with your head slightly elevated or switching sides can help alleviate this congestion.
Deviated Septum
Adeviated septumhappens when the cartilage or bone between the nasal passages is crooked.
This can cause one passage to be smaller than the other and more easily blocked.
A deviation can be minor, meaning you only notice the stuffiness when dealing with a cold or allergies.
Or, it can be more significant, meaning that your symptoms are usually obvious.
Nasal Polyps
Nasal polypsare growths within the nasal passages.
Nasal polyps usually are benign (not cancerous) but can also be cancerous.
When they become swollen, they can contribute to nasal congestion.
If your adenoids are only inflamed on one side, they can contribute to one-sided stuffiness.
This is more common in children than adults.
Unilateral choanal atresia is when this happens on only one side.
This procedure is known as aseptoplasty.
This is an outpatient surgery that generally takes 6090 minutes.
Nasal polyp treatmentincludes medication or surgery.
This can be because one nasal passage is narrower, obstructed, or more easily clogged than the other.
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