Which symptom is commonly associated with sleep apnea?

Snoring is a common symptom associated with sleep apnea due to the disruption of airflow during sleep. In obstructive sleep apnea, the muscles of the throat relax excessively and block the airway, leading to episodes where breathing is interrupted. This obstruction can cause vibrations in the throat tissues that lead to snoring. The loudness and frequency of the snoring can be significant indicators of the presence of sleep apnea.

In contrast, while insomnia can be related to various sleep disorders, it is not uniquely indicative of sleep apnea. Frequent nightmares and sleepwalking pertain to different sleep disorders and are not directly linked to the physiological changes seen in sleep apnea. Therefore, snoring serves as a direct and observable marker that often leads to further investigation of sleep apnea, making it the most relevant choice in this context.