Have you ever looked at the clock, realized you slept for eight hours, and still felt exhausted? Sleep problems are more common than many people realize, and they don't always mean you're sleeping too little. In many cases, the issue is poor sleep quality rather than the number of hours you spend in bed. Many people blame stress, work, or an old mattress. While those factors can certainly play a role, your daily habits and sleep environment may also have a significant impact.