You can access your detailed Sleep Statistics page by selecting Hours of Sleep on the Sleep Performance pillar, or by tapping your Sleep entry on the Overview pillar.
This page gives you a detailed breakdown of the previous night’s sleep, in relation to the average of the last 30 days. You can view Time in Bed, the number of Disturbances you experienced, your Sleep Latency (the amount of time it took you to fall asleep), and time spent in each Sleep Cycle. You can also see a snapshot of your raw Heart Rate data.
You can also access User Input by swiping left in iOS, or tapping the User Input tab in Android.