Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a breathing disorder occurs during sleep. OSA patients experience brief pausing of breath (apnea) during sleep. Apnea can occur as frequently as 20-30 times per hour, lasting for at least 10 seconds or more every time. Patients with less severe conditions may experience apnea a few times every hour.


Impact of Sleep Apnea

When apnea occurs, the patients appear to be struggling for breath, and then come out of sleep for a few seconds. They will then return to regular breathing pattern, change their sleeping poses and go back to sleep. The cycle of apnea will repeat throughout the night. However, the patients are neither aware of the pauses of breath, nor awakening at night frequently. Because the sleep is so interrupted and their brains have been deprived of oxygen, the patients cannot stay in focus during the day.

OSA patients do not only suffer from interrupted sleep, they also disturb their spouses/partners by giving out snores and increase their own chance of stroke and cardiovascular diseases. A Sleep-Cardiology healthcare research performed on over 6000 patients conducted in the USA shows that OSA patients have over 2 times the risk of contracting heart failure than healthy individuals. They also have 60% or 30% higher the chance of stroke or coronary heart disease, respectively.


Causes of Sleep Apnea

Infection in the nasal cavity, oral cavity, pharynx or larynx, or swelling or collapse of supportive muscles of these regions can obstruct the airway and lead to brief apnea when the patient lies down face-up. Snoring is caused by obstruction in the airway. People snore because air vibrates when it hit the soft palate when it passes through the constricted part of the upper airway. The more obstructed the airway, the louder the snore.

鼻腔 口腔 咽喉
During daytime and in upright position, air reaches the lungs through the nostrils, pharynx and larynx and the trachea without any problem. Under normal circumstances during sleep, the tissues of the airway, including a. nasal concha b. uvula and c. oropharynx have enough space for air to pass into the respiratory tract. In OSA patients, at least one of the airway tissues (green dots) swells or collapses and obstructs the airflow when they lie face up in bed. This is the cause of apnea.


Respiratory System

The channel that connects the nasal cavity and the lung is called respiratory tract or simply airway. Air inhaled from the nose passes through the nasal passage between the nasal concha, the pharynx and larynx, trachea and reaches the lungs. Oxygen is absorbed into the body and carbon dioxide is removed from the body to achieve a balanced metabolism. This collection of gaseous exchange is known as "Breathing". Oxygen that inhaled then enters our blood stream where it is transported to our cells to turn nutrients into energy. Therefore, breathing breathing is indispensable in generating energy. In resting state, a normal adult breathes 16 to 20 times in a minute. Every inhalation brings in 400 to 500 ml of air.



 Symptoms of Sleep Apnea

Obstructive Sleep Apnea patients have the following symptoms:

During SleepDaytimePhysical Conditions
Loud but uneven snores. Dry mouth or headache when awake from sleep Obesity
Breathe with the mouth Doze off frequently Hypertension
When observed by others, the patients appear to be choked & pause breathing Get tired easily
Frequent micturition Slow in response, difficulty in staying in focus


We try to provide the most accurate information for you. Please excuse us if the information we provided is incomplete or imperfect. The health information provided in this section is for your reference only. Readers are responsible to seek professional advice on their health issues or medical problems from their doctors.

The content is copyrighted. Reprint of the content is not allowed without consent from us.