Hypopnea – Partial Apnea: Episodes, Diagnosis and Effects

It is a partial apnea event where the lungs’ airflow is reduced for at least 10 seconds.

In other words, it manifests as shallow breathing that represents a decrease in airflow.

If you have only 30% to 50% of airflow, doctors will diagnose you with Hypopnea. The diagnosis will be made during a sleep study.

On the other hand, an apnea event occurs when the airflow you breathe during sleep is blocked by an obstruction of your throat.

Patients with sleep apnea must understand these medical terms. Knowing how many hypopneas or apnea events they have in a night determines if the person has mild, moderate, or severe apnea.

In addition, Hypopnea can be as physiologically disturbing as sleep apnea.

How do episodes of Hypopnea and apnea develop?

Everything starts from narrowing the upper respiratory tract, either by fatty deposits in the walls of the airways, enlarged tonsils, nasal congestion, elongated uvula, or extra flexible tissue in the back of the palate or brain damage ( central sleep apnea). All of these can cause an apnea event.


In many cases, people with sleep apnea are born with small openings in the airways, which causes respiratory obstruction during sleep – causing apnea events.

However, the more the airway narrows, the harder it is to breathe. As the size of the breath decreases, blood oxygen levels decrease, and carbon dioxide levels increase.

In the end, the increasing effort required to breathe, the lack of oxygen, and an increase in the level of carbon dioxide, cause the patient to wake up and gasp for air.

Diagnosis of sleep apnea with Hypopnea events

Sleep apnea is characterized by repetitive episodes of Hypopnea or apnea, where the upper airway is partially or obstructed.

However, ordinary people sometimes have this, and they feel perfect when they wake up. So,

How many episodes does a patient with sleep apnea have?

Sleep specialists use a simple measure called the apnea index to answer this question.

An apnea index is several episodes of Hypopnea and apneas per hour of sleep. In other words, a person who has 15 apnea events per hour of sleep would have an apnea index of 15 (AI = 15).

After your sleep test, you will receive information about your sleep quality. If you see an apnea index (AI) greater than 5, then it is considered that you have clinical sleep apnea.

This condition is closely related to sleep apnea, except that apnea is defined as a complete stop in breathing rather than a reduction in depth or breathing rate.

For this reason, many people refer to these reductions as partial sleep apnea, although this term is medically incorrect since apnea means a total cessation of breathing.

As with sleep apnea, these reductions in breathing can fall into three distinct categories: obstructive, central, and mixed.

Obstructive Hypopnea is a condition in which respiratory problems are caused by some other condition that results in partial blockage or obstruction of the airways in the nose or throat and is by far the most common of the three hypopneas.

There is usually only a reduction in airflow in obstructive Hypopnea due to an obstruction, while the breathing effort remains the same.

These obstructions can be related to any number of different factors, including:

  • Being overweight or obese
  • Deviated partition.
  • Allergies or other respiratory diseases.
  • The excess soft tissue in the back of the mouth (tongue, uvula, soft palate, enlarged tonsils or adenoids).
  • Nasal swelling and congestion.
  • Tonsillitis.
  • Smoke.
  • I was drinking alcohol before going to bed or taking sedatives and other medications.
  • Central hypopneas are related to other nervous or muscular system disorders that limit a person’s ability to breathe correctly.
  • In most cases, the reduction of breathing is related to a decrease in respiratory rate or effort due to these other conditions.

This specific disorder is quite rare, and in some cases, it not only manifests itself at night since many people also suffer from central daytime hypopneas.

The third type, mixed, refers to respiratory reductions directly related to an obstruction combined with another condition that affects breathing. In most cases, respiratory problems are initially caused by a central infection but worsen or continue due to a block.

These episodes are much more common because most people with the condition that leads to central Hypopnea also deal with one of the many factors that lead to airway obstructions, especially those due to being overweight or taking certain medications.

Effects of hypopneas in your daily life

A partial apnea can have the same detrimental effects as a total cessation in breathing, severely degrading the quality of a person’s sleep.

In most cases, the individual remains utterly unaware that he has any problems and usually sleeps throughout the night. However, most people wake up feeling like they just slept, resulting in extreme fatigue and a constant feeling of tiredness.

Many others report frequent headaches, concentration problems, difficulties remembering even the simplest things, depression, and lack of energy.

However, the biggest complaint usually comes from the person’s partner since this condition usually results in frequent and often thunderous snoring.

Conclusion … To know if your Hypopnea needs medical attention, it is essential to know how many episodes of hiccups and apneas you have in a night. The greater the number of events, the more dangerous and severe this condition is.