Definition of obstructive sleep apnea syndrome – this sleep apnea syndrome is  characterized by repetitive episodes of upper airway obstruction that occur during sleep, usually associated with a reduction in blood oxygen saturation.

Upper airway narrowing due to either excessive bulk of soft tissues or craniofacial abnormalities predisposes the patient to obstructive sleep apnea syndrome. An underlying abnormality of the neurologic control of the upper airway musculature or ventilation during sleep may be present. In some patients with neurologic disorders, a specific lesion affecting the control of pharyngeal muscles can be responsible for the development of obstructive sleep apnea syndrome.

The loud snoring typically has been present for many years, often since childhood, and may have increased in loudness before the patient’s presentation.

The snoring is commonly so loud that it disturbs the sleep of bedpartners or others sleeping in close proximity.

The patient occasionally will hear the snoring, but is usually not aware of the snoring intensity. The snoring may be exacerbated following the ingestion of alcohol before bedtime or following an increase in body weight.

Upon awakening, patients typically feel unrefreshed and may describe feelings of disorientation, grogginess, mental dullness, and incoordination.

Severe dryness of the mouth is common and often leads the patient to get something to drink during the night or upon awakening in the morning.

Morning headaches, characteristically dull and generalized, are often reported. The headaches last for 1 to 2 hours after awakening and may prompt the ingestion of analgesics.

Excessive sleepiness is a typical presenting complaint.

Most patients with the obstructive sleep apnea syndrome have an increase in the severity of symptoms with increasing body weight. Many patients, however, report that at a younger age their symptoms were less noticeable even though their body weight may have been greater.

Obstructive sleep apnea syndrome is most common in middle-aged overweight men and women. The prevalence has been estimated to be 4% for men and 2% for women.

Obstructive sleep apnea syndrome can occur at any age, from infancy to old age. Most patients present between the ages of 40 and 60. Women are more likely to develop obstructive sleep apnea after menopause.