Science has known about the concept of circadian rhythm (CR) for a long time. In short, your CR is your body's internal clock, and it regulates all of your biological processes. CR is mainly dependent upon sunlight to keep your CR regular and healthy.

Even if you don't know anything about CR, you're familiar with its effects. For instance, if you get sleepy in the mid-afternoon or if you seem to get your best work done late at night, you're being guided by your body's internal CR. That same system controls things such as your heart rate, blood pressure, and body temperature, so it's important to pay attention to your body's natural CR if you're going to be effective in your daily life.

Although scientists haven't nailed down all the factors involved, the most important factor they've identified for keeping your CR in balance is sunlight. CR is what helps keep your body alert during daylight hours and then helps you relax when night starts to fall so you'll be able to sleep. It's also your CR that wakes you up in the morning on time, even on days when you forgot to set your alarm the night before.

One of the best ways to maintain a healthy CR is to make sure your home has lots of sunlight. If you find yourself feeling somewhat out of sorts or down for no particular reason, it may be that your body is craving sunlight. A simple thing like opening the drapes and letting the sunshine in may help rebalance your CR.

A widespread sleep disorder called Seasonal Affective Disorder (SAD) has been found to be caused by a disruption in people's CR. Sometimes called the "Winter Blahs," SAD is felt most acutely during the winter months, when there's less sunlight available. This is especially noticeable in people who live in northern areas of the world, where the amount of sunlight decreases significantly during winter months, or in areas such as the Pacific Northwest, where there's a great deal of rain. Depression and sleeping difficulty are the most common effects of SAD, and it can be severe enough to cause sufferers to become suicidal.

Scientists have discovered that your CR is regulated by your body's production of a compound known as melatonin, which is a hormone secreted by the pineal gland, located between the two hemispheres of your brain. If you've been experiencing sleep difficulties, it would be worthwhile to check your melatonin level. There are melatonin supplements available over the counter, but if they don't seem to help, ask your doctor about other alternatives that may be available.

Research in CR is ongoing, but you can take the first steps toward balancing your own CR by bringing plenty of sunlight into your home and by doing your best to try to maintain a regular schedule, including going to bed and getting up at essentially the same time every day. Keeping a strict routine may be difficult, but opening the curtains in your home is easy, and it will go a long way toward helping keep your circadian rhythm in balance.