Why one nostril gets blocked in summer: main causes## Translated content from Russian to English

The Mystery of Summer Congestion: Why One Nostril Stops Breathing in the Hot Season

The summer period seems like a time of relief from colds and nasal congestion. However, some people experience a feeling that one nostril stops breathing normally specifically during summer. This can cause discomfort, headaches, and even worsen sleep. There are several possible causes for this condition.

Natural Nasal Cycle

Every person has a so-called physiological nasal cycle - one nostril works more actively, then, after several hours, the load shifts to the other. In summer, this process may be felt more acutely due to heat, stuffiness, or high humidity.

Allergy to Pollen, Dust, or Fluff

In summer, the air contains a large number of allergens: plant pollen, poplar fluff, indoor and outdoor dust. An allergic reaction can cause swelling of the nasal mucosa. Sometimes this swelling occurs unevenly - then a person feels congestion in only one nostril.

Dry Air from Air Conditioners

Frequent stays in rooms with air conditioning can dry out the nasal mucosa. This irritates the respiratory tract, causing local swelling. The nostril that is closer to the flow of cold air gets congested especially often.

Temperature Fluctuations

Sudden transitions from heat to cool environments (for example, into a store, office, or transport) are stressful for the body. The vessels of the mucosa react with spasm or dilation, local swelling may begin, especially on one side of the nose.

Deviated Septum

If the nasal septum is slightly displaced, air passes worse on one side. In summer, with minor inflammation or swelling, this defect becomes more noticeable, and there is a feeling that one nostril is blocked.

Runny Nose After Swimming

Swimming in cool water can provoke mild inflammation of the mucosa. If water gets into the nose or a person stays in wet clothes for a long time, unilateral swelling may develop.

Sleeping Positions

When sleeping on your side, blood flow increases to the lower part of the nose. This can cause temporary congestion on the side on which the person was lying.

What Can Help

Rinsing the nose with saline solution

Humidifying the air in the room

Avoiding direct contact with air conditioning

Reducing contact with allergens

Consultation with an ENT specialist if symptoms recur frequently

If congestion is observed regularly only in summer, it's worth paying attention to allergic reactions, air humidity, and habits related to cooling and swimming.