How do you know when to wake up in the morning? If you’re lucky, you’re able to get up without using an alarm clock. Have you ever felt sleepy in the afternoon? What causes these things to happen? Your internal body clock does and it is essential for your body to function. What happens when it isn’t working properly? What can you do to regulate it?

Body clock is really a broad term for several others that all have something to do with the cycles in which your body’s functions. Every organism has natural timing devices called biological clocks. They are made of specific protein molecules that work within all the cells of your body. This means they are found in almost every tissue and organ in your body.

In your brain is a master clock that coordinates the function of all these biological clocks. It’s a group of 20,000 neurons (nerve cells) that make the suprachiasmatic nucleus (SCN), and it is located in the hypothalamus area of your brain. Due to its location, it receives direct input from your eyes. Your biological clocks produce your circadian rhythm and regulate its timing.

Circadian rhythms are the physical, mental and behavioral changes you experience on a daily cycle. The primary driving force behind them is the lightness or darkness of your environment. This is why it is important your master clock receives input from your eyes. Alterations to light-dark cycles can cause your biological clocks to speed up, slow down or reset, affecting your circadian rhythm significantly.

Circadian rhythm is responsible for a wide variety of functions throughout your body. The most well-known is the sleep-wake cycle. Besides this, it helps to regulate hormones, eating habits, body temperature, heart function, kidney function, cognitive performance and many other vital functions. There are many different kinds of hormones in your body with each playing a crucial role in how it functions.

During the 24-hour cycle, all hormones will rise and fall according to your body’s needs. Two, cortisol and melatonin, help with regulating your circadian rhythm. Cortisol peaks shortly after you wake up, and melatonin peaks during the middle of the night. When this happens, it sends a message from the master clock in your brain to your biological clocks in your cells, telling them what it is time for them to do.

Within the circadian rhythm 24-hour cycle, there are thought to be three distinct periods with certain bodily functions taking place within those periods. The first period is elimination and occurs between 4:00 am and 12:00 pm. It’s when the body is cleansing itself of toxins throughout your body.

The second period is appropriation and occurs between 12:00 pm and 8:00 pm. This is the time period that your body is most efficient at digesting the food you eat, causing them to be burned up faster, so this is when you should be eating your main meals and being the most active.

The third period is assimilation and occurs between 8:00 pm and 4:00 am. This is when your body is repairing and healing from the days activities using the food that you have eaten during the day. This when you should be least active, most relaxed and asleep.

Most people’s circadian rhythm experience biggest dips in energy between 2:00 and 4:00 in the morning and 1:00 and 3:00 in the afternoon (this is why you often feel tired after you’ve had lunch). You don’t notice the swings between alertness and tiredness as much if you get enough sleep at night. However, when you interrupt the cycle of hormones, it causes them to be produced at the wrong times and at the wrong levels leading to your body’s clocks getting out of alignment.

Obviously, this cycle has evolved over thousands of years, and our bodies don’t like to deviate from it. When your circadian rhythm isn’t functioning optimally, it can cause a variety of problems, such as sleep disorders, obesity, diabetes, depression, bipolar disorder, and seasonal affective disorder.

What causes the misalignment?

Certain things can throw your circadian rhythm out of line, such as jet lag when traveling, staying up late to watch a sporting event, or getting up early to go to work to prepare for a big presentation. Even when it is just a one-time thing, it can cause your circadian rhythm to not work properly, and affect you in a variety of ways. However, there are things that we do every day that interrupt our circadian rhythm.

Since the invention and widespread use of electricity, you are able to trick your body into thinking it’s lighter longer. While this works to a certain point, it explains why we still feel tired in the evening. It’s hard to combat years of evolution. Your brain is wired to be stimulated by blue light because this is what it receives from sunlight telling you it is time to be awake and active. The problem is that your cellphone, tablet, computer, and television all emit blue light as well. So, if you use them close to the time you should be going to sleep, then you are actually stimulating your brain to remain awake, leading to difficulty sleeping.

This is why it’s a good idea to ban electronics from your bedroom, even your radio alarm clock, and keep artificial lighting lower at night. Sleeping in a completely darkened room is helpful for your body not to be stimulated. It’s also normal to sleep more during the winter and less during the summer because of the natural variation in the seasons. Since we have the capability to stay up later thanks to electricity, most of us base our sleep patterns like we are on summer time all year, which is why many of us feel tired more often.

It’s important to note that sleeping in a cool room is beneficial since your circadian rhythm lowers your body temperature at night because it is mimicking the fact that it is usually colder at night than during the day, and your body is less physically active, causing it to not produce as much internal thermal energy.

High cortisol levels cause your circadian rhythm to become disjointed. Besides, helping you wake up in the morning, cortisol is the stress hormone. This is why managing stress and finding ways to reduce it are key to getting a good night’s sleep.

On the other side, melatonin starts increasing about two hours before your body wants to go to sleep. This is why having the same bedtime and getting about 7-9 hours of sleep each night is key to keeping your circadian rhythm on its proper cycle. Certain factors can increase your melatonin production. Being active during the day is helpful, especially if it is outside. At a minimum, you should, without sunglasses, spend 15 minutes outside on a sunny day and 30 minutes outside on a cloudy day to help regulate your circadian rhythm.

Another way to boost melatonin production is by eating more organ meats and seafood because they have a high amount of tryptophan. Melatonin is made from serotonin, which is made from tryptophan.

One last major component in keeping your hormone levels stable is your blood sugar. Since your body needs glucose to survive, most hormones are very sensitive to changes in it. It’s essential to keep your blood glucose levels at a relatively constant level and avoid spikes or dips as much as possible. Don’t eat a large meal before going to bed. Avoid caffeine, alcohol, and sugary snacks for at least four hours prior to going to sleep. When you first wake up in the morning, drink a glass of water because your body is often dehydrated due to not having any fluid intake while you have been sleeping. The glass of water can help to get your metabolism going and flush out toxins.

There is no question that your circadian rhythm is essential to your body functioning properly. By doing what you can to keep it on track, you’ll be able to live your life more easily. You will also reduce your chances of having numerous chronic conditions.

Even though we have the capability of staying up late, we need to do a better job of listening to our bodies when it tells us what it needs. Rather than looking at your circadian rhythm as something that is annoying leftover from days gone by, you should accept it as a way that your body is telling you what it needs to be healthy.