Why You Can Trust CNET Here's How to Tell Your Brain Is Begging You to Sleep More
Poor sleep has significant short and long-term effects on how your brain functions. Here's how to know when your brain is asking for more sleep.
- Certified Sleep Science Coach, Certified Stress Management Coach
Not getting enough sleep is a drag. We can all agree on that. Many people might not know that sleep deprivation isn't just feeling drowsy the next day. Your brain isn't functioning as well as it should, which translates to tangible impacts on your daily life.
The connection between sleep and your brain is a big topic and can quickly become complicated, especially when you throw in words like hypothalamus and amygdala. At CNET, we've been studying sleep for years, so I'm here to help you understand what happens to the brain while we're asleep and what can happen if you're not getting enough of it.
What happens in the brain while we sleep?
The body may quiet while asleep, but the brain is surprisingly active. Before digging into the good stuff, let's establish the stages of sleep. There are two broad types of sleep -- REM sleep and non-REM sleep.
Non-REM sleep consists of four sleep stages: two stages of light sleep and two of deep sleep. Research suggests that stage two of light sleep is where the brain starts to work on memory consolidation. Deep sleep (stages three and four) is when restorative sleep happens and is essential for learning. Then there's REM sleep, which goes even further into processing memories and emotions.
Read more: Can Tech Help You Sleep Better? This Is My 3-Week Quest for Answers
There's a lot that happens in the brain only while we sleep. Your brain also does housekeeping tasks while you sleep, including removing toxins, encouraging communication between neurons and storing new information from the day. Sleep is also essential for neuroplasticity, or the brain's ability to adapt.
5 ways sleep deprivation affects your brain's functioning
Without quality rest, you can't function as well as you could on a good night's sleep. You may not have been making the connection between poor sleep and daily functionality. But it's there.
You can't concentrate
One of the first things you'll notice when you don't get enough sleep is the feeling of being scatterbrained. In other words, your thought processes are slower, and paying attention is difficult when you haven't slept well. You get confused easily and have a hard time carrying out simple tasks.
According to a study published in Nature Reviews Neuroscience, lack of sleep decreases task-related activity in the brain's frontal and parietal parts. That means you have difficulty concentrating and can't effectively block out distractions. Your capacity to sustain attention over time also decreases.
Your memory is impaired
Memory consolidation happens when we sleep. Essentially, your brain decides what's important to keep from the day and what isn't while you're in a deep sleep. The neural connections for important memories are strengthened and connected to past ones during REM sleep. Lack of sleep and fragmented sleep -- meaning you don't spend enough time in the sleep cycles -- will compromise your ability to form and recall memories. Add in the inability to concentrate, and it's a recipe for forgetfulness.
You can't learn as well
In the same way that sleep allows our brain to retain and strengthen memory, it also helps us learn. When you're tired, things don't stick because the brain isn't as effective at processing information. Without restorative sleep, the neurons in your brain don't get a chance to rest. If they stay active for too long, neuroplasticity is inhibited, and learning is difficult.
The compounding effects of poor sleep, the inability to concentrate and remember things, can make it feel impossible to learn things while you're tired.
Your mental health suffers
Not getting enough sleep directly impacts the state of your mental health. And it doesn't take much to see changes in your mood or ability to cope with stress. One study revealed that it only takes one sleepless night to cause anxiety levels to increase by 30%. It's because you're not getting enough deep sleep, which leaves you unprepared for stressful situations.
The amygdala is the emotional processing center of the brain. It becomes hyperactive, and you're unable to interpret emotion and stimuli as you should. This will leave you in a heightened state of anxiety.
Depression symptoms are also more prevalent when you're not sleeping enough. Depression and sleep are a chicken and egg situation. Poor sleep makes it difficult to regulate emotions, and experiencing depression can impact how much slow-wave sleep you get at night.
Your risk for dementia increases
In addition to helping us remember and learn, the brain has another big job while we sleep: clearing out toxins. When asleep, the spaces between the brain cells expand, allowing the lymphatic system to more effectively remove things like amyloid β-protein, which is believed to contribute to Alzheimer's disease or other dementias.
Research has suggested that short sleep (less than seven hours each night) may increase the risk of dementia in later life. A study examining data from an estimated 8,000 people found that people in their fifties and sixties who slept for less than 7 hours each night were 30% more likely to develop dementia.
The link between dementia and sleep is still being investigated, and experts cannot conclusively say that poor sleep leads to dementia. However, it's still a good idea to prioritize sleep.
Too long; didn't read?
Sleep isn't a luxury. It's a necessity for optimal brain functioning. And before you shrug off being a little forgetful or unable to concentrate, long-term sleep deprivation can increase your chances of developing dementia, heart disease, hypertension and stroke. Not to mention how poor sleep affects your reaction time and decision-making, making it dangerous to drive or operate heavy machinery.
Don't worry if you haven't been sleeping well. Establishing a quality sleep routine that can turn things around. You'll feel more like yourself after a few nights of good sleep.
Use these simple tips to get started on your better sleep journey:
- Try sleeping with noise. There are four main colors that are good for sleep -- white, pink, brown and blue.
- Stop drinking caffeine around 8 hours before bed so it doesn't keep you up at night.
- Establish a nightly routine with relaxing activities that help you unwind before bed. Try and keep it as consistent as possible to reduce stress and feelings of anxiety.
- Add moderate exercise into your routine to fall asleep faster and increase the slow-wave sleep you get at night.