Sleep apnea: description
Snoring is a common phenomenon that increases with age. Almost every second person produces the nocturnal sounds:
During sleep, the mouth and throat muscles relax, the airways become narrower, and the typical fluttering sound of the uvula and soft palate is produced – but normally this does not result in a brief cessation of breathing.
Sleep apnea is different: Here, the snorer’s breathing repeatedly stops briefly. The term “sleep apnea” comes from the Greek: “A-pnea” means “without breath”.
Sleep apnea disturbs sleep and ensures that sufferers do not wake up refreshed in the morning. This often also applies to the person in the next bed, who feels disturbed by the particularly loud and irregular snoring with the breathing pauses. Sleep apnea syndrome is dangerous because the short pauses in breathing during sleep can expand into longer-lasting, threatening cessations of breathing.
Sleep apnea as well as normal snoring belong to the sleep-related breathing disorders (SBAS). These breathing disorders occur exclusively or primarily during sleep.
Sleep apnea: Frequency
In addition, the frequency of sleep apnea increases with age.
Forms of sleep apnea
Doctors distinguish between obstructive and central sleep apnea:
Obstructive sleep apnea (OSAS).
Obstructive sleep apnea syndrome is the most common form of sleep apnea. During sleep, the muscles of the soft palate become slack. As a result, in people with obstructive sleep apnea, the negative pressure created during inhalation causes the trachea to collapse at various points in the upper respiratory tract. The air can then no longer flow freely – the sleeper gets no air for a short time.
This respiratory arrest causes the oxygen content in the blood to drop (hypoxemia), and there is a shortage of oxygen in the tissues. This causes the body to have a “wake-up reaction”: it abruptly activates the respiratory muscles of the diaphragm and chest, the heart also increases its output, and blood pressure rises. The sleeper usually wakes up briefly as a result. This awakening caused by sleep apnea is called “arousal” by physicians. When breathing resumes, this is usually followed by several deep breaths.
Central sleep apnea
The second form of sleep apnea is central sleep apnea. This form is triggered by a malfunction in the central nervous system (CNS). Here, the upper airways remain open, but the respiratory muscles of the chest and diaphragm do not move sufficiently. As a result, the affected person breathes in too little and not deeply enough. The resulting lack of oxygen alerts the brain, which immediately ensures that deep breaths are taken.
Central sleep apnea mainly affects older people. It is often harmless and usually does not need to be treated – unless it occurs in combination with heart failure or nerve disorders. Then those affected should see a doctor.
Sleep apnea: symptoms
Typical symptoms of sleep apnea are repeated cessations of breathing during sleep. The cessations of breathing last between 10 and 120 seconds and occur more than five times per hour. This is followed by periods of excessive breathing (hyperventilation) and loud and irregular snoring (when the patient is straining to catch his or her breath). Partners and relatives often notice the pauses in breathing during the night in addition to the snoring, while the affected person himself is not aware of them.
Consequences of sleep apnea
Some people with sleep apnea also suffer from anxiety or depression. In some cases, the breathing disorder leads to headaches (especially in the morning hours) and reduced sexual desire. In men, erectile dysfunction may occur.
Sleep apnea in children
Children can also be affected by obstructive sleep apnea syndrome (OSAS). The breathing disorders may also play a role in sudden infant death syndrome, experts believe.
Older children with OSAS often appear sluggish and sluggish. They often stand out at school because of poorer performance.
Sleep apnea: causes and risk factors
There are several factors that promote the development of obstructive sleep apnea syndrome. These include:
- excessive body mass index (overweight)
- Age (the frequency of sleep apnea increases with age)
- Gender (men are affected more often than women)
- Taking sleeping pills or tranquilizers (muscles in the palate then slacken more quickly and close the airways)
- Deviations in the structure of the facial skull (craniofacial features): An example is a lower jaw that is too small or falls backwards or a crooked nasal septum.
Central sleep apnea is rare and results from disorders in the central nervous system (CNS). Due to neurological damage, the control of the respiratory muscles functions poorly.
One possible cause is neuroborreliosis – a disease stage of tick-borne Lyme disease. Patients with heart failure also often suffer from central (sometimes obstructive) sleep apnea. Likewise, central sleep apnea can occur as a result of chronic kidney weakness (chronic renal failure) or shortly after a stroke.
Sleep apnea: examinations and diagnosis
Anyone who snores (often noticed by their partner, but not the sufferer themselves) and suffers from apnea during sleep should consult an ear, nose and throat (ENT) doctor. The path to a diagnosis of “sleep apnea” requires several steps – there is no “one” sleep apnea test.
The doctor will first ask you about your medical history (anamnesis), for example:
- Do you have any known pre-existing conditions?
- Do you suffer from sleep disorders?
- Are you taking any medication (e.g. sleeping pills or tranquilizers)?
- What about your alcohol consumption?
- Do you take any drugs?
- What are your sleeping habits? (if necessary, your partner knows better, which is why you should ask him or her first – or your partner can come with you to the doctor).
This is followed by a physical examination. The ENT specialist looks for anatomical abnormalities in the oral cavity and in the nasopharynx – for example, bite abnormalities (position of the jaws in relation to each other), curvatures of the nasal septum or nasal and pharyngeal polyps. The paranasal sinuses can be easily visualized with imaging techniques.
The doctor also determines your body mass index (BMI) from your height and weight.
Sometimes, clarification of sleep disorders and sleep-related breathing problems also requires polysomnography – an examination and measurement of various parameters during sleep. This usually requires you to spend one or two nights in a sleep laboratory. Doctors analyze your sleep behavior, your breathing during sleep and other factors that indicate sleep disorders (sleep apnea screening). Electrodes attached to the skin help in this process, recording, among other things, the airflow of breathing, pulse rate, the oxygen content in the blood, and the movements of the chest. Sleepiness tests may also be necessary. In the Multiple Sleep Latency Test (MSLT), for example, the patient must take a short sleep of about 20 minutes several times a day at intervals of two hours. The test records the tendency to fall asleep and the degree of daytime sleepiness.
Current medical guidelines for sleep-related breathing disorders advocate the use of home devices to aid in the diagnosis of sleep apnea.
Smartphones and smartwatches also pick up on this technology, but are typically not approved as medical devices.
Sleep apnea: treatment
To find out what treatment options are available for sleep apnea, read the article Sleep apnea – Treatment.
Sleep apnea: disease progression and prognosis
Obstructive sleep apnea should definitely be treated, because it affects health as well as professional and private life:
- Patients with daytime sleepiness are up to seven times more likely to have road traffic accidents.
- Sleep apnea is associated with hypertension, cardiac insufficiency (heart failure), coronary artery disease, and cardiac arrhythmias (e.g., atrial fibrillation).
- It also seems likely to be associated with pulmonary hypertension, diabetes mellitus, renal insufficiency and arteriosclerosis.
- Obstructive sleep apnea syndrome is generally associated with increased mortality.
In people with dementia, treatment of sleep apnea is also important because sleep-disordered breathing further promotes mental decline.
Apart from the possible health consequences, snoring and sleep apnea also place a not inconsiderable burden on the partnership.
