Circadian Rhythms: Your Body's Internal Clock

Circadian rhythms are 24-hour cycles that are part of the body's internal clock, running in the background to carry out essential functions and processes. One of the most important circadian rhythms is the sleep-wake cycle.

The Master Clock

In humans, the master clock is a group of about 20,000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN. The SCN is located in the hypothalamus and receives direct input from the eyes, which is why light exposure is so important for regulating our internal clock.

Effects on Health

Research has shown that disrupting circadian rhythms can lead to various health problems, including sleep disorders, obesity, diabetes, depression, and seasonal affective disorder. Shift workers, who must work nights and sleep during daylight hours, often experience disruptions to their circadian rhythms.

Jet Lag

When traveling across multiple time zones, our circadian rhythms remain synchronized with the original time zone, resulting in jet lag. This temporary condition can cause fatigue, insomnia, poor concentration, and digestive issues. It typically takes one day per time zone crossed to fully adjust.

Optimizing Your Circadian Rhythm

Maintaining a regular sleep schedule, getting exposure to natural light during the day, avoiding blue light from screens before bedtime, and managing meal times can all help optimize your circadian rhythm and improve overall health. Use our Calendar tool to help maintain a consistent schedule.

Chronotherapy

Chronotherapy involves planning treatment approaches around the body's natural rhythms. For example, some cancer treatments and medications are more effective or have fewer side effects when given at specific times that align with the body's circadian clock.