It's down to what's known as the 'nasal cycle'. We might not realise it, but our bodies deliberately direct the airflow more through one nostril than the other, switching between nostrils every few hours.
In many people, the nasal septum is off-center — or deviated — making one nasal passage smaller. When a deviated septum is severe, it can block one side of the nose and reduce airflow, causing difficulty breathing.
It's likely that one nostril will always feel more stuffed up than the other when you're sick. Still, after about 90 minutes to 4 hours, your nose switches sides.
Many factors can cause a blocked nose at night, including allergies; sinusitis; dry and dusty air; physical obstruction; pregnancy; viral infection; posture, and heartburn/acid reflux.
When you've got a blocked nose, try sleeping on your back with your head elevated so gravity can then help to drain away congestion. Sleeping on your side can also help keep your airways open, so you can breathe more easily. If acid reflux is causing your blocked nose, sleeping on your left side is best.
Sinusitis (also called rhinosinusitis) starts when this drainage system becomes blocked, usually from swelling due to inflammation caused by infection or allergy. Soon, your head hurts, you feel facial pressure or pain, and thick mucus clogs your nose.
Whether it's from a hot shower or piping hot cup of tea, steam can thin mucus and help it drain from your nose. For faster relief, pour boiling water into a large bowl. Cover your head with a towel, lean over the bowl, and breathe in the steam. You can do this three to four times a day.
Acupresssure Point LI 20: Located at the base of your nose, this pressure point can help relieve sinus pressure. Acupresssure Point SI18: Located where your cheekbones meet your nose, this pressure point can relieve sinus congestion.
Blowing the nose can worsen the feeling of congestion due to pressure build-up within the nostrils, which may shoot up the mucus into the sinuses instead of ejection through the nose.
In many cases, breathing out of one nostril is harmless. It often occurs due to the nasal cycle. This term refers to the spontaneous congestion and decongestion in the nostrils. As the airflow is not always equal in both nostrils, a person may feel that they breathe in through one nostril more so than the other.
“Blowing your nose is useful, but if nothing is coming out, it generally means there's not a lot of mucus.” The three common culprits behind inflammation in your nose are infections, allergies, and nonallergic rhinitis, says Dr. Alexander.
Blowing your nose to alleviate stuffiness may be second nature, but some people argue it does no good, reversing the flow of mucus into the sinuses and slowing the drainage. Counterintuitive, perhaps, but research shows it to be true.
Some natural ways to get your sinuses draining and relieve sinus pressure include drinking plenty of fluids; using a humidifier; avoiding cold, dry air; taking plenty of steamy showers; and drinking a cup of hot tea or soup.
Vicks VapoRub — a topical ointment made of ingredients including camphor, eucalyptus oil and menthol that you rub on your throat and chest — doesn't relieve nasal congestion. But the strong menthol odor of VapoRub may trick your brain, so you feel like you're breathing through an unclogged nose.