Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. There are two basic kinds of sleep apnea:
- This occurs when the body (specially the thoracic and abdomen area) tries to breathe, but blockage of airflow occurs in the upper respiratory tract.
- This can be described as lack of airflow into the lungs. However, when compared with Obstructive Sleep Apnea, Central Sleep Apnea has no movement in the chest. This pause of breathing occurs due to the brain fails to signal the muscles that control breathing.
In patients with OSAS, the upper respiratory tract is partially or fully blocked. The muscles relax during sleep. Some patients can even reach a very serious circumstance, which leads to complete blockage of the throat.
Typical OSAS patients find themselves always sleepy during the day. At night, they are woken up by breathing pauses, morning headaches and snoring. The respiratory tract can be blocked 30-100 times per hour in OSAS patients during sleep. For each blockage, it causes the patient to leave from deep sleep and enters light sleep, sometimes wake-up, until the airways are opened for breathing. The consequence is that sleeping is greatly affected. Patients find themselves always sleepy during the day. Patients with serious sleepiness can even sleep while sitting on a chair or standing.
- Upper respiratory tract abnormalities
- Neuromuscular abnormalities in throat. Sleep apnea occurs more frequent in those with tonsillar hypertrophy, jaw/tongue hypertrophy and chunky neck. Severe nasal septum deviation and other nasal obstructive diseases such as nasal polyps can aggravate OSAS. Obesity is one of the important high risk factor of OSAS. However, not all these risk factors mean that you will have OSAS. OSAS rarely occurs in patients with normal throat. Most researchers believe that OSAS patients have neuromuscular abnormalities in throat or breathing mechanism abnormalities in brain during sleep. This requires further research. Certain medical conditions such as thyroid dysfunction may also aggravate sleep apnea.
The diagnosis and treatment of OSAS is very important, because OSAS can seriously affect the patient’s health. In all Sleep Apnea patients, the oxygen saturation level in blood will decrease; whereas under normal circumstances the oxygen saturation level should be 94% or more. In OSAS patients, the level can decrease to an extremely dangerous level. Breathing pauses can occur 50-100 times within one hour in some patients during sleep. The outcome is that the patient cannot enter the deep sleep which the body needs. He/she only enters the lighter sleep.
Decreased oxygen level in this situation can cause serious health problems. Research have shown that the heart rate decreases during a breathing pause, but increases during the wake-up. Cardiac output also reduces when obstructive apnea occurs. Other cardiac problems such as arrhythmia also appear during OSAS.
Sleep Apnea can also cause elevated blood pressure, regardless of aortic pressure or pulmonary arterial pressure. In severe patients, congestive heart failure may appear. Diabetes can also occur in OSAS patients.
All of these factors are related to high mortality in Sleep Apnea patients, sudden death may even appear.