What characterizes obstructive sleep apnea?

Obstructive sleep apnea is characterized primarily by the excessive relaxation of throat muscles during sleep, which leads to the obstruction of the airway. This relaxation can cause episodes of breathing cessation or significant reduction in airflow during sleep, due to blockages in the upper airway. When the throat muscles relax excessively, they can collapse and close off the air passages, making it difficult for air to reach the lungs.

This phenomenon not only disrupts the normal flow of air but also leads to a cycle of sleep fragmentation and intermittent hypoxia, as the body repeatedly senses the lack of airflow and awakens, albeit briefly, to resume breathing. It’s this primary mechanism of obstruction due to relaxed throat muscles that fundamentally defines obstructive sleep apnea.

Other factors such as increased heart rate and high blood pressure may indeed be associated with sleep apnea, but they do not characterize the condition itself. Reduced airflow is a consequence of the muscle relaxation, while heart rate changes and blood pressure fluctuations occur as secondary effects on the body's response to the obstructed breathing.