Sleep apnea syndrome

Synonyms in a broader sense

Obstructive Sleep Apnea Syndrome (OSAS), Obstructive sleep apnea (OSA), obstructive sleep-related breathing disorder (OSBAS), obstructive snoring, sleep apnea syndrome (SAS - generic term)

English.: (obstructive) sleep apnea syndrome

Apnea: from the Greek: "respiratory arrest"; Say: "Apnoë", not "Apnö"

Spelling mistake: Sleep apneus syndrome

Definition and symptoms

Apnea means stopping breathing and is the main characteristic of sleep apnea syndrome:
The Sleep apnea syndrome is characterized by Breathing pauses in sleepthat last over 10 seconds. These pauses in breathing cause an interruption of the night's sleep, sleep apnea syndrome leads to night sweats and pronounced fatigue, concentration disorders, performance kinks and depression during the day are possible symptoms of sleep apnea syndrome.

Read more information on the topic here: Consequences of lack of sleep

Due to tiredness and the tendency to fall asleep (Microsleep) there is an increased risk of accidents during the day. In addition, the partners of patients with sleep apnea syndrome can have a loud nocturnal experience snoring to report. Likewise, the respiratory arrests are often noticed by the patient's partners. The patients themselves often give one dry mouth when you wake up in the morning.

What is an (obstructive) sleep apnea syndrome?

The term sleep apnea refers to respiratory arrests occurring during normal night sleep, which are then considered to be illness if they last at least 10 seconds and occur 10 times per hour, with a sleep phase of at least 6 hours.
In addition to the frequent obstructive form, which is described further here, in which the cause is a mechanical interruption of the flow of breathing gas through the nose or mouth (see breathing), there is also central sleep apnea, in which the cause lies in the central nervous system and which is rather rare , e.g. as a result of Lyme disease. A mixed form of the two mentioned is also possible.

Warning signs of sleep apnea syndrome

The person concerned feels exhausted in the morning, possibly suffering from a headache or dizziness, it is not uncommon for a dry mouth to occur (see: Dizziness in the morning). The is an important alarm signal abnormal daytime sleepiness, especially with monotonous activities it can lead to Microsleep come (increased risk of accidents in traffic!).
In the long run it comes to Concentration and memory disorders, depressive moods, Erectile dysfunction (impotence, erectile dysfunction) and decreased performance. Increased sweating or the urge to urinate at night can also indicate sleep apnea.

Which symptoms occur, when does sleep apnea require therapy?

Often, bed neighbors become aware of the partner's restless sleep with pauses in breathing that end with a snoring sound or sigh, and irregular loud snoring. The breathing rhythm is disturbed.

Cause of sleep apnea syndrome

In over 90% of cases, sleep apnea syndrome is caused by the upper airways:
The pharynx of the person concerned narrows with the beginning of the deep sleep phase because the pharyngeal wall muscles relax and the access to the upper airways is partially blocked. This phenomenon occurs preferentially in overweight patients and is aggravated by the consumption of alcohol, smoking or the use of sedatives. Diseases in the area of ​​the upper airways such as nasal polyps or a sloping nasal septum (curvature of the nasal septum) can promote the development of sleep apnea syndrome, as they encourage mouth breathing.

The snoring noises are caused by the collapse of the upper airways, so that patients with sleep apnea syndrome are practically always heavy snores. An examination for sleep apnea syndrome should therefore be carried out for snoreers who are very tired during the day.
Sleep apnea syndrome is caused in less than 10% of cases by central malfunctioning of breathing during sleep or arises as a result of a chronic lung disease. The mostly obese sleep anoreic patients often have additional accompanying diseases such as cardiac arrhythmias, narrowing or complete occlusion of the coronary arteries ( Coronary heart disease) or a pumping weakness of the heart (heart failure).

The high blood pressure, which around 50% of patients with sleep apnea syndrome have, is the result of increased activity of the stress-relieving nervous system, which increasingly releases the hormones adrenaline and noradrenaline: the apnea phases during sleep mean that the patient breathes in less oxygen and the body threatens to get into the situation of oxygen deficiency. The organism must therefore be driven to intensify the work of breathing. The stress-relieving nervous system does this by sending an alarm to the body through the norepinephrine and adrenaline.However, the subsequent increased work of breathing is often inefficient, so that finally there is a wake-up reaction (micro arousal), which enables normal and efficient breathing with sufficient oxygen uptake again.

Waking up at night mostly remains unconscious, but it causes fragmentation of sleep and disrupts nightly recovery, so that patients are very tired during the day and even have attacks of falling asleep. In addition, one can observe a faster pulse during sleep and cardiac arrhythmias in sleep apnea syndrome patients.

How do respiratory arrests occur and what are the consequences?

When people sleep, the entire musculature relaxes; excessive slackening of the muscles in the palate and throat can, as well as other obstacles (polyps, nasal septum curvature = septal deviation), represent a relevant barrier to the flow of respiratory gas (see breathing).

The body is repeatedly under-supplied with oxygen (hypoxia), which particularly affects the brain. If the carbon dioxide content of the blood rises at the same time (hypercapnia), central nervous waking reactions occur (so-called “arousel” or “micro-arousel”). These are usually not consciously noticed by the person concerned. Stress hormones are released, there are strong fluctuations in the circulatory parameters at night (blood pressure, heart rate), the sleep architecture and the recovery function are disturbed. Ultimately, this also causes high blood pressure (arterial hypertension) during the day, it leads to daytime sleepiness and the need to fall asleep, due to the heavy load on the cardiovascular system, the risk of heart attack and stroke increases.


The distinction between obstructive and central sleep apnea syndrome is important with this clinical picture, since the causes are different and a causal therapy, i.e. a cause-oriented therapy, should be sought as a priority.

Read more on this topic at: Therapy of sleep apnea syndrome

In obstructive sleep apnea syndrome

With obstructive sleep apnea syndrome, the problem is usually caused by a mechanical obstruction of the upper airways. While the tonsils or palatine tonsils are usually enlarged in children, the causes can be more diverse in adults. The obstructive sleep apnea syndrome in adults is most frequently associated with obesity, but the tonsils or uvula can also be enlarged or the nasal septum crooked. Last but not least, enlarged turbinates can also lead to these complaints.
The treatment of choice for obstructive sleep apnea syndrome is therefore surgical removal or, if necessary, correction of the disruptive anatomical structure. In addition, CPAP ventilation is usually indicated during the night in obstructive sleep apnea syndrome. CPAP stands for "Continuous positive airway pressure" and consists in the fact that air with positive pressure is continuously fed into the body so that the relaxed throat muscles cannot collapse completely even during exhalation and thus close the airway. One also speaks of a pneumatic splint, since the airways are splinted with the help of air pressure. Sometimes the designation nCPAP is also used, the "n" stands for "nasal" and is a specification for the type of application of the breathing apparatus.
In some cases, the BIPAP ventilation mode is preferred. BIPAP stands for "Biphasic positive airway pressure" and differs from CPAP in that there are two different overpressure levels for inhalation and exhalation. The pressure during exhalation is slightly lower than with CPAP and is particularly indicated when the intrathoracic pressure is to be kept as low as possible due to heart disease or the ventilation of the lungs needs to be improved.

In central sleep apnea syndrome

In the case of central sleep apnea syndrome, on the other hand, there is no obstruction of the upper airways, rather the control loop for the respiratory drive in the brain is disturbed. Often these patients develop a so-called Cheyne-Stokes breathing and central sleep apnea syndrome is often associated with other diseases such as heart failure or after a stroke. Therapy then depends primarily on the underlying disease. The treatment of a central sleep apnea syndrome is therefore often the therapy of heart failure.

With both forms of sleep apnea syndrome, it also makes sense to avoid or reduce accompanying risk factors. In addition to weight control and the optimal setting of blood pressure, this also includes reducing alcohol and nicotine. In addition, it is important to maintain a certain sleep hygiene in order to give your own body the opportunity to prepare for the rest phases and to be able to relax as well as possible. In the case of obstructive sleep apnea syndrome, it can also be helpful to avoid lying on your back while you sleep in order to mechanically prevent the airways from being obstructed.


An operation for sleep apnea syndrome is usually only indicated for the obstructive type. Correction of the nasal septum is a common procedure. Just like the removal of nasal polyps or the reduction in size of the turbinates, it is a measure to improve nasal breathing.

If the problem is one floor lower, for example in the throat area, the tonsils can be surgically removed. It is also possible to shorten the uvula, as well as tighten other structures of the soft palate. This type of procedure is also known as Uvulo- palato- pharyngoplasty (short: UPPP).

A somewhat more complex and lengthy operation is the forward displacement of the upper and lower jaw. However, this method can achieve good results in the long term, especially in young patients with obstructive sleep apnea syndrome. The last option is a tracheotomy, also known as a tracheotomy. The trachea is cut at the neck, creating a path for the air that is independent of the mouth and throat. This access can remain closed during the day. At night, breathing can be ensured with the help of a tube. Overall, however, this method is used extremely rarely, as it is usually associated with considerable restrictions for the patient.

Is it curable?

The chances of a cure are of course always dependent on the individual findings. In principle, however, with consistent adherence to the therapy and a change in lifestyle, a significant improvement can be achieved up to and including the disappearance of the symptoms. Weight loss alone usually leads to a significant alleviation of the symptoms. If this is carried out in a controlled manner and maintained over the long term, it can even cure an obstructive sleep apnea syndrome. Not using alcohol and nicotine can also have a significant impact on the healing process. And last but not least, the blood pressure should also be in the normal range so that a cure can be striven for.

In the case of pronounced anatomical findings, cause-oriented therapy in the form of a surgical intervention can of course greatly improve sleep apnea symptoms or even make them disappear completely. Surgical widening of the airways in particular can, under certain circumstances, completely eliminate the problem, so that in some cases one can speak of a cure. Only the central sleep apnea syndrome has fewer prospects of a cure, as this clinical picture usually arises from other chronic diseases. As a rule, these are already in a state that is no longer curable, but if the therapeutic measures are consistently followed, it is possible to control the symptoms and prevent further sequelae.


If CPAP therapy is carried out regularly in sleep apnea syndrome, restful sleep is also possible, which has positive effects:

Patients are less tired during the day, their performance increases and the risk of accidents is reduced, as microsleep is less common. In sleep apnea patients with high blood pressure, a decrease in blood pressure of about 10mmHg can occur.

The patients are more balanced and the sleep behavior of the partners improves, as they are often concerned during the apnea phases that breathing will stop completely and not just pause. In addition, by stopping the partner's snoring, the quality of their night's sleep can also be increased.
How it can be achieved is explained in detail in our next article: How can you prevent snoring?

Degree of disability (GdB)

The degree of disability (GdB for short) represents a measure of the impairment of an individual in everyday life due to the consequences of illness. Obstructive sleep apnea syndrome can also have far-reaching consequences for those affected and its consequences can be partially recognized with the aid of the GdB. There are some guidelines that can be used as a rough guide. An obstructive sleep apnea syndrome without nightly ventilation obligation can be counted with up to GdB 10, while a CPAP or BIPAP therapy with up to GdB 20 is recognized. If therapy is not possible or if the condition remains bad despite exhausted therapeutic measures, this can lead to recognition of a severe disability (i.e. GdB 50). However, when determining the GdB, all factors of a patient must always be taken into account in order to be able to depict as complete a picture of all functional impairments as possible. The above values ​​are therefore only to be understood as guidelines.


A Sleep laboratory examination is used for the reliable diagnosis of sleep apnea syndrome.
The patient sleeps one night in the sleep laboratory and during sleep, in addition to the brain waves, the oxygen content of the blood, the frequency of breathing, the pulse and blood pressure as well as the flow of breathing are measured. With all this information, an overall picture of the body's function during sleep can arise in a patient with sleep apnea syndrome.

In addition, for sleep apnea syndrome patients it is necessary to see an ear, nose and throat doctor who will examine the patient for possible breathing obstacles: Nasal polyps, very big Pharynx, a sloping nasal septum or a very large tongue can lead to breathing problems during sleep and are therefore referred to as "breathing obstacles".

If there is sufficient suspicion of the presence of an obstructive sleep apnea syndrome, there is the possibility of an outpatient diagnosis by means of so-called Non-laboratory monitoring systems (NLMS).
These are compact devices that record parameters such as breathing sounds, oxygen saturation in the blood, heart rate and respiratory flow (nasal flow) during the night that the person concerned spends at home. The data are evaluated in the doctor's office or in a sleep laboratory.
In addition, this diagnosis can also be carried out in one sleep-laboratory can be carried out by spending one to two nights and, in addition to the above-mentioned data, e.g. also an EEG (electro-encephalogram, the recording of brain waves), Long-term blood pressure, Cardiac currents (EKG) and video recordings can be made (Polysomnography).

Occurrence in the population

About 4% of men and 2% of women over 40 years of age have sleep apnea syndrome and the disease becomes more common with age. The majority of patients are overweight.

Which patients are affected? Patient profile:

Men are affected far more often than women.
In addition, about 2/3 of those affected are overweight, whereby the overweight (obesity) can also be a consequence of the nocturnal apnea.
Congenital or acquired obstacles in the upper airways, such as polyps, curvature of the nasal septum, enlarged tonsils or a large angle of the lower jaw (dolichofacial facial type) also cause the disease.
Drinking alcohol in the evening or taking some sedative or sleep medication that cause the throat muscles to relax at night are other causes.