Why is one nostril always blocked?

A nostril feeling “blocked” most of the time is often due to the normal nasal cycle: your body naturally alternates swelling and decongesting the nasal tissues on each side every few hours. You usually don’t notice it unless you have allergies, a cold, dry air, or irritation making the swelling more obvious.

Common reasons one nostril feels persistently blocked include:

• Normal nasal cycle, especially noticeable when lying on one side
• Allergies or hay fever causing swollen nasal lining
• A cold, sinus infection, or post-nasal drip
• Deviated septum, where the wall between nostrils is off-center
• Nasal polyps or enlarged turbinates
• Irritation from smoke, dust, strong smells, dry air, or overuse of decongestant sprays

What you can try safely:

• Use saline spray or a saline rinse
• Run a humidifier if your air is dry
• Treat allergies with an appropriate antihistamine or nasal steroid spray if you commonly have sneezing/itching/runny nose
• Avoid using decongestant sprays like oxymetazoline for more than 3 days unless a clinician tells you to
• Sleep slightly elevated or switch sides if it worsens when lying down

See a doctor or ENT if it is almost always the same nostril, lasts more than a few weeks, follows an injury, causes frequent sinus infections, nosebleeds, loss of smell, facial pain, or if you have a one-sided foul-smelling discharge. Seek urgent care if you have severe facial swelling, high fever, vision changes, severe headache, or trouble breathing.