Unilateral nasal congestion is the sensation of one nostril feeling blocked or stuffy while the other remains clear. This common experience occurs due to various physiological processes and external factors. Understanding these causes can help address the discomfort, which is often not a serious medical concern.
Reasons Your Nostril Might Be Clogged
Nasal Cycle
The normal physiological nasal cycle is a common reason for a single congested nostril. Turbinates in the nasal passages regulate airflow by alternately swelling and shrinking. This natural cycle means one nostril typically experiences more airflow while the other becomes more congested, alternating every few hours. This subtle shift often goes unnoticed unless other factors, such as an infection or allergies, amplify the congestion.
Viral Infections
Common viral infections like colds or the flu can lead to inflammation and swelling within the nasal passages, which might affect one side more acutely. When the body fights an infection, increased blood flow to the nasal region causes greater swelling and mucus production. This heightened response can make congestion more pronounced in a nostril already in a congested phase of the nasal cycle.
Allergies
Allergies, or allergic rhinitis, are a frequent cause of unilateral congestion. Exposure to allergens like pollen, dust mites, or pet dander triggers an immune response, leading to inflammation and swelling of the nasal lining. This reaction can be more pronounced in one nasal passage, resulting in blockage, often accompanied by itchiness and clear nasal discharge.
Sinusitis
Sinusitis, an inflammation or infection of the sinus cavities, can cause one-sided nasal blockage. If a single sinus cavity becomes inflamed or infected, swelling and mucus accumulation can restrict airflow through the adjacent nostril. This condition often presents with pressure or fullness around the eyes, nose, or forehead on the affected side.
Deviated Septum
A deviated septum is a structural issue where the thin wall of cartilage and bone separating the nostrils is off-center. This misalignment can make one nasal passage narrower, rendering it more susceptible to blockage. A deviated septum can be present from birth or result from a nasal injury, often leading to difficulty breathing more noticeable on one side.
Nasal Polyps
Nasal polyps are soft, non-cancerous growths that can develop in the nasal passages or sinuses. Linked to chronic inflammation, they can cause unilateral obstruction if larger or more numerous on one side. Nasal polyps can contribute to a persistent stuffy or runny nose and may also reduce one’s sense of smell.
Foreign Object
A foreign object lodged in one nostril, particularly in children, can cause immediate and persistent blockage. Small items like beads, food, or toys can be inserted, leading to irritation and obstruction. This blockage is often accompanied by a foul-smelling or bloody discharge from the affected nostril.
Vasomotor Rhinitis
Vasomotor rhinitis is a non-allergic and non-infectious condition where nasal blood vessels overreact to environmental triggers. Factors such as changes in temperature, humidity, or exposure to irritants like strong odors can cause the nasal passages to swell, leading to unilateral congestion.
Positional Congestion
Positional congestion can explain a temporarily clogged nostril, especially noticeable upon waking. When an individual lies on their side, gravity can cause blood and mucus to pool in the lower nostril, leading to increased congestion. This type of blockage usually resolves relatively quickly after changing position or moving around.
When to Consult a Doctor and What You Can Do
Consult a healthcare provider if unilateral nasal congestion persists for more than 10 days to two weeks, or if symptoms worsen. Seek medical attention for severe pain, a high fever, or bloody or foul-smelling nasal discharge. Other concerning signs include vision changes, such as double vision or swelling around the eyes, which could indicate a more serious underlying issue.
For mild, temporary unilateral congestion, several self-care measures can provide relief. Saline nasal sprays or rinses help thin mucus, clear irritants, and moisturize dry nasal passages. A humidifier adds moisture to the air, loosening thick mucus and easing breathing discomfort. Drinking plenty of fluids supports hydration and keeps nasal secretions thinner. Avoiding irritants like tobacco smoke or strong chemical odors can prevent worsening congestion. Over-the-counter decongestant nasal sprays offer short-term relief, but they should only be used for three to seven days to prevent rebound congestion.