Sleep is an inevitable part of our lifestyle but only a few people do. Sleep is something many of us find hard to achieve sometimes. In fact, around a third of adults struggle with sleep at least once a week. Learning about the science of sleep can give us some ideas to try and make sleep come a little easier.

There are lots of different theories when it comes to the ‘WHY’ of Sleep. A combination of these theories is the most likely explanation. Exploring what happens when we’re sleep-deprived is a good way of identifying the ‘Why’ of Sleep. Unfortunately, long-term sleep deprivation is a risk factor for obesity, diabetes, high blood pressure, heart disease, strokes, mental illness, poor memory, focus and concentration, clumsiness, and a weakened immune system.

Cognitively, we could notice that our reactions lag and our ideas get disorganized after a terrible sleep. Thinking, paying attention, and maintaining our mood is challenging. The fact that regions of our brain stay dormant while we are awake when we are sleep-deprived is one of the causes of these challenges.

When we’re asleep, our brain’s waste-clearance system clears out waste from our central nervous system and toxic by-products that have built up in our brain over the day. This is important because it helps our brain to work well when we’re awake. Our nerve cells exchange information and organize themselves. This encourages normal brain activity.

Our brain can transfer knowledge from working memory, also known as short-term memory to our longer-term memory while we sleep. This only applies to information that it deems necessary. Unneeded details are forgotten. A crucial component of our memory and capacity to learn new information is this process. It is simpler for the brain to learn, remember, solve problems, be creative, make decisions, focus, and concentrate when it is well-rested.

Our bodies are active while we are sleeping. It produces new tissue, regenerates muscles, replenishes energy, and creates proteins. Lack of sleep may lead to weight gain. This is due to a drop in our “hunger hormones” while we are sleeping. These hormones can become imbalanced if we don’t get enough sleep. We may unknowingly overeat as a result of our elevated levels of hunger and suppression of our feelings.

A hormone called insulin regulates the amount of glucose in our cells. Healthy cells readily absorb glucose (sugar). We use less glucose while we are sleeping. Maintaining the health of our cells, enables our body to regulate the total levels of blood glucose, so preventing insulin resistance.

“Cytokines” are proteins that our bodies produce when we’re sleeping. These proteins assist our body fight illness by producing antibodies and immune cells. This is one of the reasons we require more sleep when we are anxious or ill.

Sleep is important for our heart health, too. Weight gain and insulin resistance are risk factors for heart disease. As is high blood pressure – which is made worse by lack of sleep, because our blood pressure reduces when we’re asleep. Cortisol is a hormone that’s released when we’re awake. High levels of cortisol are a further risk factor for heart disease. Overall, sleep plays a vital part in maintaining a healthy heart.