Jet lag, shift work, and other sleep rhythm disorders can disrupt your circadian rhythm, leaving you sleepless. Below, we discuss a few of these circadian sleep rhythm disorders and how they can impact your overall health.
Also known as our “body clock”, the circadian rhythm is a biological cycle that tells our bodies when to sleep, when to wake up, and when to eat, among other things. It regulates many of our natural, physiological processes and is extremely important in maintaining our overall health and wellbeing. According to WebMD, brain wave activity, hormone production, and cell regeneration can all be linked to this internal body clock.
A study by the UCLA Sleep Center found that genetics play a key role in our circadian rhythms. However, this body clock is mainly affected by different environmental cues such as sunlight and temperature. Your body clock is determined by the presence of natural light over a 24-hour period as well as fluctuations in internal body temperature.
For example, people with normal sleep-wake cycles feel ready to wake up when the sun comes out and start feeling tired when the sun goes down (a process that many people take for granted). Cooling of the body’s core temperature can also initiate circadian rhythm sleep triggers, while warming in the morning may initiate wakefulness.
There are a variety of factors that can throw this body clock off, causing you to have problems sleeping at night. Rhythm disruptions can make you feel sluggish, disoriented and sleepy throughout the day.
Intrinsic vs. Extrinsic Sleep Disorders
Circadian rhythm sleep disorders can be broken down into two basic categories: intrinsic, or built-in, disorders and extrinsic, or circumstantial, disorders.
Intrinsic sleep disorders occur when an individual’s internal body clock is “off” and can manifest themselves in a variety of ways, including:
- Falling asleep and rising earlier than normal
- Falling asleep and rising later than normal
- Falling asleep later and later each day
- Fragmented sleep patterns
Extrinsic sleep disorders occur when an individual’s circadian rhythm is in-sync with the 24-hour cycle of lightness and darkness. However, their internal body clock has been disrupted by work hours, school, or travel demands.
Common Circadian Rhythm Sleep Disorders
Jet Lag
Jet lag is the most common contributor to circadian sleep problems. Jet lag occurs when an individual travels to a location with a new time zone, typically a location that is two time zones away from home. Because individuals must adjust to a new sleep-wake cycle in a new time zone, it disrupts their circadian rhythm, potentially causing insomnia, indigestion, irritability, and poor concentration.
For some travelers, it can take almost a week to adjust to the new time zone, but others can adjust within a couple days. Prepare yourself by adjusting your sleep patterns a few days before the trip.
Shift Work Sleep Disorder
Having varying work schedules is another cause of circadian sleep disorders. People who work the early morning or night shifts must force their brain to stay awake when it wants to go to sleep. These shift workers tend to get less sleep overall and usually experience fragmented sleep. Some people find it very difficult to handle this sleep-wake pattern for any length of time, while others may adjust to this schedule fairly easily.
Advanced Sleep Phase Disorder (ASP)
ASP is usually found in aging adults, with roughly 1% of middle-aged or elderly people experiencing ASP in their lifetimes. This disorder causes melatonin levels and body temperatures to cycle much earlier than others, making individuals feel sleepy earlier in the evening (6:00 to 8:00 PM), which often leads to an earlier bedtime. People with Advanced Sleep Phase disorder also tend to wake up earlier and have trouble getting back to sleep.
While the cause of advanced sleep phase disorder is not completely understood, there appears to be a strong genetic link. Scientists have found that people with ASP have a 50% chance of passing it onto their children. And while this disorder is not deemed “dangerous” or “unhealthy” by the medical community, it can have negative effects on an individual’s family, work, or social routines.
Delayed Sleep Phase Disorder (DSP)
On the other end of the spectrum is Delayed Sleep Phase disorder (DSP). DSP occurs when your circadian rhythm is delayed. People with DSP are unable to fall asleep at a normal time (at night). Many people with DSP tend to stay awake until 1:00 to 6:00 AM and sleep until 10:00 AM to 2:00 PM, which can interfere with work, school, or other commitments.
DSP typically develops in adolescence and persists into early adulthood, with approximately 15% of teens and adults experiencing it within their lifetimes. Similar to ASP, DSP also has a genetic link. Studies show that individuals with a family history of DSP are three times more likely to have it than someone with no family history of the disorder.
DSP can also be caused by environmental factors. For example, a lack of sunlight exposure in the morning and overexposure to sunlight at night can sometimes lead to the development of DSP.
Tips for Getting a Better Night’s Sleep
While you should always discuss ongoing sleep problems with your doctor, some helpful tips to try on your own include:
- Adjusting your normal sleep times a few days before an evening shift or business trip and allowing for extra time to adjust to a new schedule
- Ensuring that your schedule includes time for rest when traveling
- Avoiding caffeine and nicotine before bed
- Getting regular exercise
For more tips on how to get a better night’s sleep, check out our blog post on tips and tricks to improve sleep hygiene!