Obstructive sleep apnea (OSA) is defined as the occurrence of at least 5 episodes per hour of sleep during which respiration temporarily ceases. Although OSA is a relatively common medical condition, it is believed that more than 85% of patients with clinically significant OSA have never been diagnosed.

This is thought to reflect the fact that many patients with symptoms of OSA are not aware of their heavy snoring and nocturnal arousals. The cardinal features of OSA include signs of disturbed sleep such as snoring and restlessness, interruptions of regular respiratory patterns during sleep, and daytime symptoms such as fatigue or trouble concentrating that are attributable to disrupted sleep patterns at night.

It is estimated that as many as 1 of 5 adults has at least mild symptoms of obstructive sleep apnea, while 1 of 15 has moderate to severe symptoms.

What happens in OSA?
OSA is caused by repetitive bouts of upper airway obstruction during sleep as a result of the narrowing of respiratory passages. The most common site of obstruction is the nasopharynx. It is important to differentiate OSA from the less common central sleep apnea, which is caused by an imbalance in the brain's respiratory control centers during sleep. While the pathogenesis of OSA is thought to be multifactorial, anatomic defects are thought to play a major role.

Certain physical characteristics that may contribute to OSA include obesity, thickened lateral pharyngeal walls, nasal congestion, enlarged uvula, facial malformations, micrognathia, macroglossia, and tonsillar hypertrophy.
Obesity contributes to airway narrowing through fatty infiltration of the tongue, soft palate, or other areas surrounding the airway

Symptoms
Common symptoms include snoring, awakening from sleep with a sense of choking, morning headaches, fitful sleep, decreased libido, as well as a history of hypertension, cerebrovascular disease, renal disease, diabetes, or gastroesophageal reflux disease

Treatment
Treatment of OSA depends on the severity, duration, and cause of the patient's symptoms as well as the patient's lifestyle, comorbidities, and overall health, First-line therapy for most patients with OSA continues to be the use of continuous positive airway pressure (CPAP). This therapy maintains adequate airway patency; it not only immediately reverses apnea and hypopnea, but also decreases somnolence and increases the quality of life, alertness, and mood.

Given that the condition is undiagnosed for 85% of patients with sleep apnea, it is important for clinicians and patients alike to recognize and deal with the early signs and symptoms of obstructive sleep apnea.

Dr P Harsha Vardhana Varma Penumatsa
Qualification : MBBS,M.D
Specialty: Chest Physician