We often talk about what dreams “mean,” attempting to interpret the contents of what our brains conjure up while we’re sleeping and ascribe some greater meaning to them. But what about sleep quality? Do your dreams say anything about your quality of sleep? The answer is somewhat complicated, but it’s a tentative “yes.” You just have to paint in broad strokes, and realize that context matters.
Humans go through five different stages of sleep, each of varying deepness. The first one — a light one — covers the initial transition from waking to sleeping; the second, also light, sees our muscles relaxing, our body temperature dropping, and our breathing and heart rate slowing down as we fall further asleep; the third and fourth cover the deepest levels of sleep, during which we’re difficult to wake up while our bodies work on healing and repairing themselves; and during the fifth, known as rapid eye-movement (REM) sleep, we do most of our dreaming. We move through this cycle several times a night — unless it’s disrupted, which can result in feelings of grogginess the next day.
But do those dreams we have during the REM stage tell us anything about how well we’re actually sleeping? Sort of. A lot of dream elements actually have no effect at all on your sleep quality, and vice versa. For example, dreaming in color versus in black and white doesn’t have any sort of link with how good your sleep is; nor does whether or not you remember your dreams in the first place. Even lucid dreaming usually isn’t known to have an effect on your sleep quality, although some of the techniques you can use to train yourself in it might. (The “waking back to bed” technique, for example, involves purposefully disrupting your sleep cycle, which can have an adverse effect on the quality of your sleep for that night.)
However, there are some broad categories of dreams which can sometimes indicate whether you’re getting healthy or poor sleep. If you wake up feeling either incredibly well-rested or groggy and tired, what you remember of your dreams might be able to tell you why that is.
1. Pleasant Dreams
If your dreams are usually pleasant, joyful, or relaxing, odds are that your quality is terrific, according to a 2016 study published in the journal Sleep. Over five nights, the researchers observed 24 participants — 12 with primary insomnia and 12 with healthy sleep patterns — as they slept, collecting data regarding the quality of their sleep from polysomnographic recordings. Meanwhile, information on the participants’ dreams was gathered in two ways: Through dream diaries kept by the participants throughout the duration of the study, and by waking the participants up when they were in REM sleep and asking them to describe what they had been dreaming about. (This second tactic was employed only during two nights of the five-night study.) And, lo and behold, the good sleepers’ dreams were associated with more positive emotions, generally being described by the sleepers as pleasant, joyful, and happy. The insomnia sleepers, meanwhile, characterized their dream content much more negatively.
As Health Central points out, the sample size for this study was pretty small; however, the link is still significant: If you generally sleep well, your dreams will typically be quite enjoyable.
2. Vivid Dreams
Vivid and colorful dreams could indicate that your sleep quality isn’t actually that great. As neurologist Mark Mahowald of both the University of Minnesota and the Minnesota Regional Sleep Disorders Center put it to Scientific American in 2007, “When someone is sleep deprived, we see greater sleep intensity, meaning greater brain activity during sleep; dreaming is definitely increased and likely more vivid.” What’s more, a 2005 study published in the journal Sleep found that when participants were deprived of REM sleep had much more vivid dreams when they did enter REM: They typically described the intensity of these dreams as being an eight or nine on a nine-point scale — nine being the most intense they could possibly be.
3. Dreams In Another Language
Obviously, the results of this one depend on whether or not you’re already fluent in multiple languages — but for what it’s worth, if you’re in the process of learning a new language and you start dreaming in that language, it might be an indication that you’re making good progress in your efforts. By extension, it also means that you’re probably getting some pretty solid sleep. There’s evidence that REM sleep helps us learn how to do new things by aiding in consolidating our memory; what’s more, according to one study (which, granted, is pretty old — it was published in the 1990s — but which is still notable), in a group of participants taking a six-week French language immersion program, the people who picked up the language the quickest started dreaming in French earlier and more robustly, while simultaneously experiencing increases in REM sleep percentages.
Nightmares can be indicative of a lot of things when it comes to your sleep quality; what your nightmares in particular means for how well you’re sleeping depends on your own unique circumstances. If you just have the occasional bad dream, that’s usually nothing worry about; they often arise as a reaction to stress in your waking life and don’t necessarily need to be treated (other than by, say, a good snuggle with your favorite pet).
However, if you have frequent nightmares, that might be an indication that something else is going on — and it's probably affecting your quality of sleep. Remember that study that found that pleasant dreams are linked with good sleep? Yes? Then you’ll also recall that negative dreams were found to be linked to insomnia. What’s more, a study performed in 2015 that gathered its data in similar ways — over three nights, via polysomnographic recordings, using a pool of 17 people with frequent nightmares and 17 people with healthy sleep patterns — found that, although actual sleep architecture wasn’t affected by frequent nightmares, the participants who experienced these nightmares “reported worse sleep quality, more waking problems, and more severe insomnia” than their healthy sleep patterned counterparts.
5. Dreamless Sleep
There’s a difference between not remembering your dreams and actually not having dreams. Most people dream, even if they can’t remember their dreams; what’s more, whether or not you remember your dreams actually doesn’t say anything at all about the quality of your sleep. However, according to John S. Antrobus, a retired psychology and sleep research professor who spoke to the Huffington Post on the subject of dreams in 2017, you might not dream at all if your sleep is very poor.
Since dreaming mostly occurs during REM sleep, a complete lack of dreams could indicate that you aren’t dropping into REM at all — which means that your sleep cycle is way out of whack. REM usually begins about 70 to 90 minutes into the sleep cycle, so if you never reach it, you’re probably waking up with a great degree of frequency. If you have sleep apnea, this might be something you experience regularly.
(It’s true, by the way, that people do dream in other stages of the sleep cycle besides REM sleep; however, researchers aren’t sure how much they dream in these other stages, or how frequently. Just, y’know, for reference.)
Not getting much, if any, REM isn’t great in and of itself, but it’s worse when you consider that there’s evidence to “support the notion that REM sleep has an important role in daytime function,” as Very Well puts it. REM may be one of the ways our minds and bodies help us learn new skills, for example, so without it, picking up anything you don’t already know, from physical activities to, say, vocabulary words, can be a lot harder. We can also problem-solve in REM sleep, so being deprived of it might make it more difficult for us to work through difficult scenarios and situations in our lives.
If you’re experiencing trouble sleeping, it’s worth talking to a medical professional about it; there are also a variety of free and low-cost sleep resources available online these days, although it’s probably best not to self-diagnose if you can help it. Sweet dreams!