We’ve all been there: you’ve drifted off for a good night’s sleep only to find yourself pursued by monsters in a dark forest, or perhaps you’re giving a presentation to an enthusiastic crowd. These dream experiences can feel intensely real, but what exactly is happening within your body when you dream?
Family doctor Natalia Hapych, MD, unravels the mystery of dreaming and explains what truly occurs when our subconscious takes us on those wild nighttime adventures.
What is dreaming, exactly?
Dreaming is a state where we create, perceive, and experience thoughts and sensations during sleep. While this is a universal human experience, understanding what happens to your body during this process is a bit complex.
“The dream state, especially during the Rapid Eye Movement (REM) stage of sleep, is a time when your brain is very active,” Dr. Hapych explains. “While you may be physically still inside, there is a lot going on.”
But what exactly happens in your body when you enter this active dream state?
Brain activity during dreams
You may be surprised to learn that your brain is buzzing with activity while you’re dreaming. Contrary to what you may assume, your brain doesn’t ‘turn off’ when you sleep. In fact, certain parts of your brain — particularly those associated with emotions, memory, and creativity — are even more active during REM sleep when most dreaming occurs.
“During REM sleep, your brain waves resemble those of someone who is awake,” Dr. Hapych says. “The areas of the brain that control emotions, behavior, and memory formation are particularly active.”
Body paralysis during dreams
Have you ever wondered why you don’t physically act out your dreams? Well, it turns out your body has a protective mechanism in place for this.
“When you enter REM sleep, your brain sends signals to inhibit most voluntary muscles, inducing a state of paralysis,” explains Dr. Hapych. “This keeps you from acting out your dreams and potentially harming yourself or others.”
However, this paralysis doesn’t extend to all parts of the body.
The exception: your eyes and breathing
While your body is largely immobile during REM sleep, two things continue to move: your eyes and your respiratory system.
“Your eyes move rapidly in different directions during REM sleep — hence the name Rapid Eye Movement sleep,” Dr. Hapych clarifies. “Your breathing also becomes more rapid and irregular during this stage.”
Impact on heart rate and blood pressure
It’s not just your brain and eyes that are working overtime during REM sleep; your heart rate and blood pressure may also increase. This is due to the heightened brain activity and emotional intensity that can occur during dreams.
“Your heart rate can become as elevated during dreams as it would if you were in a stressful waking situation,” Dr. Hapych explains. “Likewise, your blood pressure can also increase, but these changes are typically harmless.”
Dreaming and memory
Dreaming is thought to play a significant role in memory processing and learning. Your brain is busy consolidating and processing information from the previous day, forming new neural connections that help with learning and memory.
“Dreaming can help with problem-solving and consolidating memories, which is why you might wake up with a fresh perspective or solution after sleeping on an issue,” Dr. Hapych affirms.
The dark side: Nightmares and sleep disorders
While dreaming can be an interesting and beneficial process, it can also lead to sleep disturbances like nightmares and sleep disorders such as REM sleep behavior disorder, where people act out their dreams, sometimes violently.
“If you frequently experience nightmares or have symptoms of a sleep disorder, like feeling exhausted despite a full night’s sleep or acting out dreams, you should seek medical attention,” Dr. Hapych warns.
To dream or not to dream?
Dreaming is an important part of your sleep cycle, contributing to emotional processing, memory consolidation, and brain health. It might seem a bit unsettling — your brain working overtime, your heart racing, your body in a state of paralysis — but rest assured, this is your body’s natural and healthy response to the REM sleep phase.
So, the next time you find yourself in the throes of a particularly vibrant dream, remember what Dr. Hapych says, “Dreaming, no matter how wild or strange, is a normal and essential part of sleep.”
Dream on, knowing that your body is hard at work, even in the realm of sleep, doing its part to keep you healthy, happy, and ready for a new day.