• Is it usual?
• Nasal cycle
• Nasal congestion
• Nasal obstruction
• Structural differences
• Contacting a doctor
• Summary

People may only be able to breathe through one nostril due to congestion, allergies, a blockage, or natural changes in the nasal cycle. This is not uncommon and may get better on its own.

The nasal cycle refers to the way tissue inside the nose regulates the size of the air passages, opening or narrowing each side to allow more or less air inside throughout the day.

This is an unconscious process people may not notice, but it can become noticeable if there are irregularities or if one side becomes blocked.

This article explores what may lead a person to breathe through one nostril, what other symptoms could occur, and when to contact a doctor.

Is it usual to only breathe through one nostril?

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Yes, to an extent. It is typical for each side of the nose to dilate or contract over time.

The air flowing into one nostril is often greater than the other due to a process known as the nasal cycle. At times, a person may feel they are breathing more through one nostril than the other.

However, people can also have other types of blockage that may affect airflow on one side of the nose. For example, mucus, polyps, and other growths can block the nose. People can also have structural differences inside the nose that affect airflow, such as a deviated septum.

If a person can only breathe through one nostril consistently over time, an underlying cause may need treatment.

What is the nasal cycle?

The nasal cycle is the unconscious sequence of congestion and decongestion of the nasal cavity during the day. When congestion occurs in one nostril, decongestion occurs in the other.

The autonomic nervous system (ANS) is responsible for the nasal cycle. In many people, the ANS spontaneously switches the dominant nostril throughout the day.

During the nasal cycle, unequal blood flow in the nostrils causes the tissue in one nostril to fill with blood and block that nostril while the other remains open.

There are four different types of nasal cycle:

• Classic: This occurs when equal decongestion and congestion occur with a constant total volume.
• Parallel: This type takes place when congestion or decongestion occurs in both nostrils at the same time.
• Irregular: This is where equal decongestion and congestion occur with a constant total volume, but there is no regular pattern.
• Acyclic: This happens when the total nasal volume and nasal volume in each nostril do not differ.

A person’s nasal cycle may change for various reasons. For example, lying down can affect the nose, narrowing the passageways. Age, humidity, hormones, and some medical conditions may also affect a person’s nasal cycle.

A 2021 reviewTrusted Source also suggests that congestion arising from the nasal cycle may act as a defense mechanism against respiratory viruses.

Nasal congestion

Nasal congestion occurs due to swelling and inflammation in the nose. It can also occur due to excess mucus and fluid, which may contribute to the blockage.

Some common causes of nasal congestion includeTrusted Source:

• infections, such as colds or sinus infections
• allergies, such as dust mites, pollen, or mold allergies
• hormonal fluctuations, which may result in congestion during pregnancy or before a period

Nasal obstruction

Nasal congestion is not always a response to an irritant, pathogen, or allergen. It sometimes occurs because something is blocking the nasal passages.

A person experiencing nasal obstruction may present with lower airflow and a feeling of “fullness” in the nostrils. Potential causes of nasal obstruction include:

• Nasal polyps: Nasal polyps describe outgrowthsTrusted Source, or fleshy swellings, of the nasal mucosa lining that can cause breathing difficulties.
• Foreign objects: Nasal foreign bodies may lodgeTrusted Source in the nostrils and block the airflow. These scenarios commonly occur in children and may include objects such as batteries and magnets.
• Tumor: Certain types of tumors can develop in the nostrils or the sinuses, which can block airflow in the nostrils. These tumors could be benign or cancerous. The most commonTrusted Source is squamous cell carcinoma,

Structural differences

Sometimes, one nostril can become blocked or more difficult to breathe through because of changes in the structure of the nose or throat. These can include:

• Deviated septum: A deviated septum is when the nasal septum is off-center rather than exactly in the middle. Reduced airflow in one nostril is a potential symptom.
• Injuries: Injuries to the nose, such as fractures, can change the inside of the nose. Sometimes, this results in a narrower or blocked nostril. Previous surgeries may also have this effect if there is scarring or complications.

When to contact a doctor

A person needs to seek the advice of a doctor if they experience persistent difficulty breathing through one nostril.

Contact a doctor right away if an individual also experiences:

• facial pain or pressure, such as in the cheeks, under the eyes, or across the brows
• loose or painful teeth
• pain or pressure in the ear
• persistent, unexplained tiredness or fatigue
• a fever
• nosebleeds
• severe snoring or sleep apnea, which is when breathing stops temporarily during sleep
• a lump or sore inside the nose or mouth that will not healTrusted Source
• vision changes, such as double vision or the eyes pointing in different directions
• numbness or tingling

Summary

In many cases, breathing out of one nostril is harmless and often occurs due to the nasal cycle. This term refers to the spontaneous congestion and decongestion in the nostrils.

In other cases, a person may experience a nasal obstruction or congestion, which may block airflow in one or both nostrils. This can occur for many reasons, such as infections, inflammation, polyps, hormonal changes, or injury, among others.

As such, it is important that people are aware of other symptoms, such as changes in vision or smell, nosebleeds, headaches, and fevers, which may suggest an underlying problem.

A person needs to consult their doctor if they notice other symptoms or breathing becomes difficult.

Last medically reviewed on December 6, 2024