Dreams can tell us a lot of things: teeth falling out means stress, being naked at work indicates vulnerability, and spiders on your mattress means you're worried about... well, spiders. But can your dreams tell you how well you're actually sleeping at night?Most dreams occur during the REM sleep stage, when your brain lights up and immerses you in a series of strange, unpredictable stories. Because dreaming is a completely normal part of the sleep cycle, a dream-filled night is often simply a sign that your brain is doing exactly what it's supposed to do.However, experts say there is one crucial factor that determines whether your dreams mean you're sleeping well or not: how you feel the next day. If you wake up feeling fatigued, or if you constantly remember waking up mid-dream, then your sleep quality might be suffering.Here, sleep experts explain the science behind your dreams — and how to tell what your dreams really mean for your sleep quality.Key takeaways: At a glanceDreaming occurs during REM sleep: This is a vital stage for memory consolidation and emotional regulation. REM sleep is when your brain is most active during the night.Sleep cycles: Dreaming is a normal part of sleep and is often a sign that you're moving through the stages of sleep.The warning sign: However, if you feel like you're regularly waking up from a dream, it might be a sign that you're experiencing unwanted late night wake ups.The one crucial factor: Dreams don't indicate sleep quality. If you wake up feeling refreshed after a dream-fulled night, your sleep is probably fine. But if you feel fatigued the next day, it can mean your sleep is being disrupted at night.How to sleep better when dreaming: Using a relaxing bedtime routine and a consistent bedtime can help improve sleep quality.When do we dream?