Blocked airways: This is why only one nostril should be closed when you have a cold

A blocked nose is particularly annoying because it makes breathing difficult and often leads to poor sleep.

Those affected can often observe that only one nostril is blocked – but why is that?

This is the nasal cycle

If you close your nostrils one after the other and breathe in deeply each time, you will notice that breathing through one nostril is much easier.

One nasal concha is always in a resting phase while the other is working. Doctors observed this phenomenon as early as 1895.

Dr. Michael Deeg, specialist in otorhinolaryngologyexplains the nasal cycle as the alternating swelling and shrinking of the mucous membrane and erectile tissue in both sides of the nose.

This process takes place continuously and independently of external stimuli. A cycle lasts between 30 minutes and 14 hours. But what does this mean for a cold?

That’s why only one nostril is blocked at a time

The nasal cycle occurs unconsciously. In other words, you don’t even notice that only one nasal concha is active at a time. However, this is different when you have a cold.

Then, due to the swollen nasal mucosa and the alternating nasal cycle, it feels as if only one side is blocked.

The function of the nasal cycle

“During the nasal cycle, the mucous membrane and the erectile tissue on one side of the nose are always swollen, while the other side is in the working phase. During this working phase, a much higher air flow enters the nose than during the resting phase,” explains Dr. Michael Deeg.

The swollen state during the resting phase minimizes the amount of air that reaches the mucous membrane. Therefore, the mucous membrane releases significantly less moisture into the air during the resting phase.

Since air can enter the nose unhindered during the working phase due to the reduced swelling, the mucous membrane requires even more moistening during this phase.

“The resting phase therefore serves to relax and regenerate the nasal mucosa. During this phase of regeneration, the mucosa not only saves moisture, but also energy. The nasal mucosa primarily plays a role as a protective device against inhaled foreign bodies and pathogens,” says Dr. Michael Deeg.

“Their cilia transport foreign substances away from the body. The regeneration processes ensure that the mucous membrane remains functional. The ability to regenerate is particularly important for restoring protective functions after colds or infections,” says the expert.

This affects the nasal cycle

One of the most common complaints related to the nasal cycle is nasal hyperreactivity. This phenomenon occurs when the natural nasal cycle is disrupted by contact with external stimuli.

Naturally, the mucous membrane of the nose reacts to certain influences with difficulty breathing through the nose, sneezing or similar phenomena.

In this context, doctors differentiate between specific and non-specific hyperreactivity. In specific hyperreactivity, the patient reacts excessively to allergens.

If, on the other hand, it reacts to environmental stimuli such as smoke, fumes or cold air, this is referred to as nonspecific hyperreactivity.

The ENT expert points out that both “inflammation and disturbances of neural control play a role in hyperreactivity. The production and release of the body’s own substances such as neurotransmitters changes and the receiving receptors of the vessels and nerves or glands overreact.”

What helps with one-sided swelling

If the nose is swollen on one side without any external stimulus, you have to take action because nasal breathing is usually still sufficient.

“In principle, however, the use of isotonic or hypertonic saline solutions is an option to reduce swelling in the nose in a gentle way,” recommends Dr. Michael Deeg.

If your nose is blocked for a longer period of time, you should see a doctor who can make a reliable diagnosis.