Humans need sleep. This is unfortunate from an hours in a day perspective but sleep does wonderful things for us. Sleep allows your body to heal and recharge. We are not machines meant to run full bore for 24 hours a day.

Sleep is involved in healing and repair of our hearts and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke. Sleep leaves us refreshed and alert when we wake up.

Sleep is involved in healing and repair of our hearts and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke.

Sleep leaves us refreshed and alert when we wake up.

Sleep also helps the body remain healthy and stave off diseases. Without enough sleep, our brains cannot function properly. Read that again. It is not functions less well. It is 'cannot function properly'. This looks like less abilities to concentrate, to think clearly, and to process memories.

Not getting enough sleep has been linked to a higher risk for certain diseases and medical conditions, like obesity, type 2 diabetes, high blood pressure, heart disease, stroke, poor mental health, and early death.

How does our body know when to sleep?

We have an internal “body clock” which regulates our sleep cycle. This clock controls when we feel tired and ready for bed or refreshed and alert. Our body clock is a 24-hour cycle known as the circadian rhythm. After waking up from sleep, we will become increasingly tired throughout the day. These feelings will peak in the evening leading up to bedtime.

This sleep drive – also known as sleep-wake homeostasis – may be linked to adenosine, an organic compound produced in the brain. Adenosine levels build up during the day as we become more tired, and then the body breaks down adenosine during sleep.

Light also influences the circadian rhythm. Your brain wants to know if it is 'day' or 'night' and it uses the amount of light you see to figure that out. The brain contains a special region of nerve cells known as the hypothalamus, and a cluster of cells in the hypothalamus called the suprachiasmatic nucleus, which processes signals when the eyes are exposed to natural or artificial light.

As natural light goes down in the evening, your eyes see that, and the suprachiasmatic 'sees' that and tells your hypothalamus which then releases melatonin. Melatonin is a hormone that induces drowsiness. When the sun rises in the morning, your eyes see it, the suprachiasmatic 'sees' it, which tells your hypothalmus which then releases cortisol, a hormone that promotes energy and alertness.

You are probably 'lack of sleep drunk'

You know how drunk people are full of confidence and don't realize they are drunk? The same thing can happen with sleep.

It seems some people can develop a sort of tolerance to chronic sleep deprivation. Their brains and bodies struggle due to lack of sleep, but they may not be aware of their own deficiencies because less sleep feels normal to them.

You may feel fine with only a couple hours a night, but your brain and body are getting punched repeatedly in the face.

You need more sleep.