How Light Affects Our Sleep: Daylight vs. Artificial Light

Overview Different types of light have different effects on us and our biological clock. It is natural to be exposed to bright daylight when we wake up, and various processes in our body follow the day-night rhythm, where the day is activity time and night is the time for rest. Artificial lights from lightbulbs and … Read more

Can We Learn While Sleeping? Hypnopaedia: Myth and Reality

Overview Hypnopaedia (also spelled as hypnopedia) means learning new information while sleeping. The idea of hypnopaedia was largely popular in the 1950s, and since then, companies have sold many audio-cassettes and CDs intended for sleep-learning. It was popular among famous and ordinary people who wanted to improve their image, learn a new language or quit … Read more

Sleep And Memory – How Sleep Improves Our Memory And Helps Us Learn

Overview Sleep has long been linked with an ability to successfully remember and learn things. Although scientists claim that there are many questions unanswered and many processes not fully understood, there has been a significant amount of research and interesting, unambiguous discoveries as to what sleep does for our memory. Sleep deprivation always shows negative, … Read more

The Relationship Between Hormones And Sleep

Overview Some hormones are known to make us feel tired, help us relax and fall asleep; whereas the others depend on the quality and length of our sleep. Hormone levels rise and drop throughout the day and this fluctuation is usually directly or indirectly related to our circadian rhythm (biological clock). Hormones ensure we have … Read more

Insulin and Sleep – Do Sleep Problems Cause Insulin Resistance?

Insulin regulates blood glucose throughout the day and night. Between 4 and 8 am, there is a surge in glucose – however, if insulin is able to do its job properly, it takes care of this situation. Our body consumes the least glucose during REM (rapid eye movement) sleep and the most when we are … Read more

How Estrogen Affects Our Sleep

Overview Estrogen (sometimes spelled oestrogen) is an important reproductive hormone which effects the sleep – both in men and women. Women produce more estrogen than men, which is natural because estrogen plays major roles in the menstrual cycle and pregnancy, as well as in the later stages of a woman’s life. Adult men have about … Read more

Body Thermoregulation and Sleep

Overview You may have noticed that during hot, summer days it seems impossible to fall asleep without the AC. And maybe sometimes when it is late at night and past your bedtime, apart from feeling tired, you also feel cold. How are these things connected to your sleep? Throughout the day and night, your brain … Read more

Testosterone And Its Role In Our Sleep

Overview Although an important hormone for male health, testosterone is also present in women. With good and quality sleep, our bodies are able to replenish this important hormone. Testosterone can play its role successfully when balanced properly – excessive or deficient amounts of it are linked to numerous problems in both men and women. Adult … Read more

Why Do We Sleep?

Overview There hasn’t been a single answer to this question yet because sleep is incredibly complex with numerous functions and processes occurring during sleep. Although physically quite inactive, our mental activity is not to be ignored. Our minds prepare us for future learning, we store information from short-term into long-term memory, we dream – here’s … Read more

How Much Sleep Do We Need?

Overview The amount of sleep which is considered necessary for health and functionality is usually taken from the National Sleep Foundation recommendations. These recommendations do not appear to be simple numbers, like stating that you need 8 hours of sleep and that is that. How much sleep a person needs depends on their age, personal … Read more

What Is GABA And How Does It Affect Your Sleep?

Overview Unlike other neurotransmitters like serotonin and dopamine, GABA (Gamma-Aminobutyric Acid) doesn’t seem to enjoy the popularity it deserves. GABA is one of the most highly employed inhibitors in our central nervous system. What this means is that GABA prevents certain neurotransmitters from being effective, or at least, from being fully effective. This way, GABA … Read more

Sleep Without Feeling Rested: Non-Restorative Sleep

Overview Restorative sleep is defined as sleep which lasts a recommended amount of time, in which a person has gone through all stages of sleep, followed by a feeling of refreshment, clear-mind, and physical restfulness upon waking up. Opposite to restorative sleep is non-restorative sleep, which doesn’t provide us with a feeling of refreshment. Non-restorative … Read more

Sleep and Dopamine

Overview Dopamine is frequently associated with positive emotions and a feeling of euphoria. However, researchers have discovered other interesting functions of dopamine – for example, its role in adverse events, where it carries out an important task in helping learn how to avoid negative situations. Dopamine can be used to treat people with Parkinson’s disease … Read more

Deep Sleep – Basics You Need To Know

Overview Deep sleep is one of the Non-REM stages of our sleep and it is veiled by mystery. Not much has been discovered about the effects of deep sleep – although we are aware of some of the physiological and psychological benefits, as well as the negative impact of deep sleep deprivation. However, there is … Read more

Excessive Daytime Sleepiness

Overview If you have trouble waking up, feel tired throughout the entire day (not only after lunch), have trouble concentrating and performing your daily tasks, and struggle to stay awake, you are likely to be experiencing Excessive Daytime Sleepiness. This is not a sleep disorder, but rather a symptom. EDS may suggest you haven’t had … Read more

Energy Use During Sleep – Do We Burn Calories While Sleeping?

Overview In short – yes, we do. Our bodies need the energy to support the activity of our vital organs, such as the heart and lungs, which keep working while we sleep. During deep sleep, or slow-wave sleep, our body cells are restored as the human growth hormone is released. Our brains are very active … Read more

REM Sleep – How It Works and What The Benefits Are

Overview REM sleep (REMS) has long been a field of interest for both the public and scientists who wanted to know more about what exactly happens during our sleep and why it is so. One of the reasons why REM has drawn so much attention may be the fact that out of all sleep stages … Read more

The Four Stages Of Sleep And Sleep Cycles

Overview After we fall asleep, our body goes through different stages. These stages then repeat cyclically, and each of them is characterized by certain brain waves, body temperature, responsiveness, ability to dream. Stages of sleep and sleep cycles were first discovered and recorded after the invention of EEG (electroencephalograph), which was used to detect brain … Read more

Healthy Sleep Habits – A Guide For Parents

Overview Does your child experience sleep problems? Depending on their age, the type of problems may vary. There are some things every parent should know about their child’s sleep habits – for example, many parents of sleep-deprived children are not even aware of this problem. Sleep deprivation further leads to mental health issues – frequent … Read more

Chronotypes – What They Are and What You Can Do About Them

Overview Have you ever arrived to work on a Monday morning and realized there is one energetic coworker with bright eyes and a smile on the face? On the other hand, there is one latecomer always looking drowsy, eyes swollen, with a cowlick or two. You could say there are an early bird and a … Read more

Sleep and Creativity – Can Certain Sleep Habits Make You More Creative?

Overview Despite sleep taking one-third of our time, it remains a mystery for us. We know that sleep deprivation is bad for health. However, we have limited knowledge about the relationship between sleep and mental processes. We know that some people sleep less, others have difficulty in going to sleep, while others may sleep well. … Read more

Sleep Debt – Can You Make Up Lost Sleep?

Overview This is a concept that defines cumulative loss of sleep during a specified period – it is about chronic sleep deprivation. Thus if you are sleeping an hour less than necessary for feeling fresh and energetic, and it continues for a week. Your sleep debt is equal to 7 hours. Sleep debt is still … Read more

Sleep Deprivation – How Losing Sleep Can Ruin Your Health

Overview Chronic sleep deprivation is not a disease, but a cause. Quite often due to personal lifestyle choices, night shift job, other habits, people get deprived of sleep at night. Sleep deficiency often occurs when humans intentionally shorten night rest, thus compromising on its duration. Excessive daytime sleepiness, headaches are common symptoms. Chronic deprivation leads … Read more

Biphasic Sleep – Is Sleeping Twice Better For Us?

Overview This simply means sleeping twice during the 24 hours. It means having a shorter rest during the night and sleeping again during the daytime. Siesta is something that comes to the mind immediately when we talk about sleeping twice in a day. Biphasic sleep differs a bit. In siesta, people sleep for an hour … Read more

Polyphasic sleep: Can Ultra-short Sleep Phases Work For Us?

Overview Sleep is polyphasic when a person sleeps multiple times a day. In most cases, a person would have one long sleep phase (monophasic sleep schedule) followed by numerous ultrashort sleep phases or naps. “So, how many times do you sleep? What is your sleep schedule?” Reply in most instances would be “One.” In modern society, … Read more

Circadian Rhythm and Adrenocorticotropic Hormone (ACTH)

Overview Circadian rhythm is not merely about sleep and wake cycles. The deeper one goes into the topic; better a person understands that almost every bodily process has a rhythm. During the daytime, humans need more energy, better stress handling abilities. While in the evening, the body must relax, before one goes to bed. Adrenocorticotropic … Read more

Homeostasis and Sleep Propensity

Overview Sleep is most well-known physiological process, and yet most challenging to understand and study. We need to sleep long enough, and well enough for healthy life. Homeostasis means constant state. It is a term used in the study of human body working, a field called physiology. Thus homeostasis simply means that body tries to … Read more

Heart Rhythm Problems During REM Sleep

Overview Even though arrhythmias may not pose an immediate threat to life, they may indicate the presence of some disease. It means complete health check must be done in those with such a problem. In young men, athletes, episodes of sinus bradycardia (abnormal slowdown in heart rate) may occur. In most cases, it is a … Read more

Circadian Rhythm and Sleep

Quick Overview It would be an oversimplification to say that people sleep when it is dark, and stay awake in the light. Yes, to some extent humans are hardwired to sleep at a particular time, under the influence of certain environmental triggers. It is also true that internal factors play an important role too. Research … Read more