Why do we talk in our sleep? Is it dangerous to wake up a sleepwalker? The mystery of years has finally been solved

Calculated based on 24 hours a day and an average of 8 hours of sleep per night, a person spends 1/3 of his life in bed. So what happens to various parts of the body when we sleep? What happens to the body if we don't sleep well? Why do some people talk in their sleep? With these curiosities, let's learn about sleep...

When sleeping,

What is the body doing?

Sleep consists of two distinct physiological states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep. Different sleep stages appear to have different functions, but why we sleep is still not fully understood.

Babies spend half of their sleep time in REM sleep, but by the age of two this proportion drops to a quarter.

REM sleep is thought to be particularly important for the developing brain. During non-REM sleep, brain activity slows down and people who wake up during this stage may feel groggy.

pituitary

During non-REM sleep, the pituitary gland produces growth hormone and secretes prolactin. This counteracts the effects of dopamine to reduce overall arousal levels.

heart

When sleeping, the pulse rate of a person decreases by 10 to 30 beats per minute compared to the daytime, and the blood pressure decreases accordingly. In this case, less blood flows to the brain and more blood flows to the muscles.

Oral

During sleep, saliva production decreases, which reduces the need to swallow. 5% of adults grind their teeth at night, mainly during the early stages of sleep.

Limbs

The extra blood flow during the day causes the arms and legs to swell slightly. Muscles become paralyzed during dreams, but between dreams, a person changes sleeping position about 35 times a night.

lung

The throat muscles relax, so the airway narrows when you breathe in. This causes snoring, or pauses in breathing for a few seconds.

bladder

Vasopressin levels increase. This reduces the amount of urine collected in the bladder to between 1/3 and 1/2 of the normal level during the day.

Lack of sleep,

What happens to your body?

Sleep is not just a passive rest, the body uses this rest time for necessary repair and growth, and even a short change at night can have a negative impact on health. Studies have found that long-term lack of sleep can double the risk of fatal cardiovascular disease, weaken the immune system and increase the likelihood of obesity by 30%.

Overall, those who regularly slept less than five hours a night were 15% more likely to die in any given year.

Eye bags

Increased levels of the stress hormone cortisol lead to increased blood flow to the skin. This can appear as dark, puffy lumps under the eyes because the skin is thinner here than elsewhere on the face.

Emotional coping and regulation

MRI scans show that the amygdala, a region of the brain responsible for regulating emotions, tends to overreact to negative events when sleep deprived. Bipolar disorder has also been linked to disrupted sleep.

diabetes

When you feel tired, your glucose metabolism slows down, which can increase your risk of type 2 diabetes.

Heart disease

A complex interaction between stress hormones, increased blood pressure, and decreased glucose metabolism can increase your risk of heart disease.

obesity

Elevated ghrelin levels (the appetite hormone) stimulate eating 25% more and a preference for carbohydrate-rich foods, increasing the risk of obesity.

Muscle aches and cramps

Neurotransmitters in synapses accumulate during daytime activity, and without enough sleep to regulate them, muscles may twitch erratically.

Can't fall asleep even when you're too tired? Yes!

It’s entirely possible to feel very tired and have trouble falling asleep at the same time. Certain life stresses and health issues can make us feel exhausted but also make it difficult for us to relax and fall asleep. Additionally, missing a regular sleep schedule can disrupt our natural rhythms, which can make us feel very awake during the hours when we would normally sleep.

Some parents may have firsthand experience with finding that their babies are "too tired to sleep." This happens when babies stay awake for longer than their little bodies can handle, making it difficult for parents to settle them down.

Dreaming affects

The quality of our sleep?

Studies have shown that frequent nightmares are associated with poorer perceived sleep quality. Nightmares can cause anxiety, which makes it difficult to fall asleep and get back to sleep after waking up.

The link between dreaming and sleep quality is bidirectional. When you wake up from a dream, you are likely to remember it clearly. So if you don't sleep well and wake up multiple times during the night, you can recall the content of your dreams, which may help you fall asleep again quickly.

Why do we talk in our sleep?

When we sleep, there is a brain mechanism that blocks dream-related neural activity from triggering speech or body movement, but the system is not perfect. Sometimes the signals get through anyway, which can result in mumbling and sometimes even logical speech (and sleepwalking).

Sleep talking is a complex, often grammatically correct thing. Its content can be influenced by recent events in the sleeper's life, but can also be very strange and nonsensical.

However, sleep talking itself is nothing to worry about, although it is often more likely to occur when you are under increased stress or have other psychological problems.

Wake up the sleepwalker

Is it dangerous?

When a person sleepwalks, they will be awake and perform complex behaviors while lacking consciousness and may even have their eyes open and staring blankly, which can be very unsettling to anyone who encounters them.

Sleepwalking, also known as somnambulism, is a partial arousal from a deep sleep. This usually occurs during the non-rapid eye movement (NREM) stage of sleep, which usually occurs in the first half of the night, which explains why sleepwalking often occurs during this time.

Children are more likely to sleepwalk than adults due to the physiological makeup of sleep. The overall prevalence of sleepwalking varies widely, with one analysis estimating that up to 7% of the population experience it.

As for whether it is dangerous to wake a sleepwalker, it is not recommended to do so forcefully, as this may cause the person to become disoriented or even react violently. However, in some cases, it may be appropriate to gently wake someone who has finished sleepwalking and put them back to sleep, which can prevent them from entering another sleepwalking phase.

If you spot a sleepwalker, it’s best to take them back to bed rather than waking them up.

Sleeping with eyes open

Is this normal?

It is not normal, but there is a condition called nocturnal blepharitis that causes the sufferer to be unable to close their eyelids during sleep. This condition has been reported to occur in up to 5% of adults. It can be caused by a variety of factors, including protruding eyes or eyelid abnormalities.

There are also unexplained conditions that cause you to sleep with your eyes open. Protruding eyes at night can make it difficult to close your eyes, and can cause eye pain or even more serious problems, such as corneal ulcers. If you wake up with red or painful eyes, or if someone has told you to sleep with your eyes open, be sure to consult your doctor.

Blind man in a dream

Can you see things?

People who are born blind or who become blind early in life (before the age of about five to seven) do not experience visual imagery during their dreams. People who become blind later in life often retain some visual imagery during their dreams—but not as much as people with normal sight.

A study by Danish researchers found that the longer a person has been blind, the less likely they are to experience visual images in their dreams. While people who are born blind may not be able to see during sleep, they are more likely to experience hearing, smell, taste and touch in their dreams than sighted people.

Reviewer of this article: Chen Haixu, Deputy Director and Master Supervisor of the Second Medical Center of PLA General Hospital

Source: World Science (ID: World-Science)

Compiled by: Shell

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