What is a key indicator of sleep apnea identifiable through a sleep study?

The presence of snoring is a key indicator of sleep apnea identifiable through a sleep study because snoring is often associated with the airway being partially obstructed during sleep. In the context of sleep apnea, obstructive sleep apnea in particular is characterized by repeated instances of airway blockage leading to interrupted breathing patterns, which can result in loud snoring. During a sleep study, known as polysomnography, monitoring will often reveal snoring patterns that correspond to episodes of apnea or hypopnea, making it a tangible and observable signal of sleep-disordered breathing.

While low energy levels during the day can be a consequence of inadequate sleep or disrupted sleep patterns, they are not a direct indicator identifiable during the sleep study itself. Likewise, frequent nightmares, which may relate to different sleep disorders or psychological issues, are not specific to sleep apnea. Sudden limb movements may indicate other conditions such as restless legs syndrome or periodic limb movement disorder, rather than being a direct indicator of sleep apnea. Thus, snoring remains the most closely linked observable sign that can be monitored and analyzed through the data collected in a sleep study.