“Sleep quality is different from sleep quantity. Sleep quantity measures how much sleep you get each night, while sleep quality measures how well you sleep.

Measuring sleep quantity is simple, as it’s quick to determine if you’re getting the recommended amount of sleep per night (usually defined as 7-9 hours for adults). Measuring sleep quality is a little more of an art than a science. Generally, good sleep quality is defined by the following characteristics:

• You fall asleep soon after getting into bed, within 30 minutes or less.
• You typically sleep straight through the night, waking up no more than once per night.
• You’re able to sleep the recommended amount of hours for your age group.
• You fall back asleep within 20 minutes if you do wake up.
• You feel rested, restored, and energized upon waking up in the morning.”.

Sleep Foundation (https://www.sleepfoundation.org/sleep-hygiene/how-to-determine-poor-quality-sleep)