Jet Lag and Sleep

 

 

Learning Objectives

 · Define and discuss the term “Jet Lag”

· Explain the cause of Jet Lag

· Identify the steps that can be taken to prevent or minimize the effects of Jet Lag

· List and discuss the steps that can be taken to “treat” the symptoms and side effects of Jet Lag

 

Overview

Jet lag, or desynchronosis, is a temporary condition that some people experience following air travel across several time zones in a short period of time. This causes the traveler's internal clock to be out of sync with the external environment. People experiencing jet lag have a difficult time maintaining their internal, routine sleep-wake pattern in their new location, because external stimuli, like sunshine and local timetables, dictate a different pattern. For this reason, one can feel lethargic one moment and excited the next. Jet lag creates a double bind for vacationers and business people who must cross several time zones to reach their destination, but who are also intent on maximizing sightseeing or productivity. As travelers attempt to adjust their internal clock to a new external environment, symptoms result with varying intensity.

Jet lag (desynchronosis) occurs while rapidly crossing time zones, or, more specifically, it occurs after crossing the Earth’s meridians. Meridians demarcate geographic position in relation to the Earth’s poles and, ultimately, define time zones. Jet lag is a unique sleep disorder because its onset is not necessarily caused by abnormal sleep patterns, like insomnia. Travelers who sleep normally prior to transmeridian travel are not immune to jet lag; the symptoms result when a person’s internal clock attempts to acclimate to a new external environment. This acclimation involves circadian rhythms that, among other functions, are associated with the body’s management of sleep.

Signs and Symptoms

In addition to the “tired-wired,” “soar-crash” feeling that travelers experience after long, rapid air travel, there are numerous symptoms that may occur with jet lag, such as insomnia, daytime fatigue, stomachaches, headaches, irritability, and decreased awareness. The degree of disruption varies greatly among people; some may not be bothered at all. Jet lag is a transient sleep disorder and is classified differently than other, more serious disorders. Although jet lag occasionally lasts for a week or more, travelers usually return to their normal sleep-wake pattern after a day or two. For many travelers, jet lag can catalyze the effects of certain conditions associated with the head and nervous system that are not related to specific sleep-wake patterns. For example, many symptoms attributed to jet lag are actually caused by the environment of the airplane--dry air (humidity in an airplane is very low), pressurization, noise, vibrations, and a cramped environment. These symptoms may include dry eyes, dry and irritated nose and sinuses, headaches, earaches, muscle cramps, and abdominal distention (bloating). Occasionally, dizziness or swollen feet and ankles may occur.

Circadian Rhythms

Circadian rhythms pertain to changes in body function that occur throughout a 24-hour period. Circa is the Latin word for “about,” and diem is the Latin word for “day.” The body operates with many circadian rhythms, such as body temperature regulation, endocrine (gland and hormone) function, airway function, and kidney (renal) function.

For instance, body temperature slowly rises throughout the day, drops dramatically around midnight, and begins to rise again before 6 a.m. These changes in temperature are often felt during fever, when fluctuations are intensified by high body temperature. The body also regulates breathing patterns. So patients with asthma often have more bronchoconstriction and more difficulty with their asthma during the night when airway function fluctuates to compensate for sleep.

Mental alertness and the propensity to fall asleep are regulated by circadian rhythm. There are two peak times of day at which a person is most susceptible to falling asleep, 3 a.m. to 5 a.m. and 3 p.m. to 5 p.m. This circadian tendency has serious ramifications in our society. There are a disproportionate number of automobile accidents between 3 a.m. and 5 a.m. compared to the number of people on the road at these times. This increase in automobile accidents is partly attributable to conflicts between circadian rhythms and, for instance, atypical lifestyle or shift work constraints that put drivers on the road at these times. Decreased vigilance can combine with sleepiness and result in an accident. Apparently, circadian rhythms are evident in all types of activity.

Most people have experienced the urge to fall asleep in the late afternoon, after eating lunch. It is not necessarily the food that makes people want to fall asleep at this time, but the time of day. Again, the routines of environment conflict with circadian rhythms, which can influence one’s ability to function.

All the rhythms mentioned above occur in humans within a cycle of approximately 24 hours. The exact length of the cycle is not known and is probably slightly longer than 24 hours, perhaps 24.7 to 25 hours. These natural rhythms occur even in the absence of daylight or darkness. Studies in which people live without any way of knowing what time of day it is have shown that these people continue to follow a 24-hour schedule. That is, they sleep for about eight hours, and their waking activity levels correlate with those found for individuals under normal conditions of time and light-dark cycles. It seems the influence of circadian rhythm is unavoidable.

People naturally synchronize their internal clocks with day-night cycles, which allows them to be awake during the day and to sleep during the night. The body regulates this chiefly through the eyes. Light stimulates nerves in the retina that pass a signal through a chain of nerves to the brain. Some of these nerves feed the hypothalamus, a part of the brain that regulates body temperature, water and sugar ratios, and fluid secretions and which houses the suprachiasmatic nucleus, a bundle of nerves that controls the body’s circadian rhythms. When, for example, bright light stimulates the optic nerves, the optic nerves send the signal to the suprachiasmatic nucleus, which then triggers circadian rhythms, resulting in the synchronization of the body's 24-hour cycle with the earth's 24 hour cycle.  

Can Jet Lag be Avoided?

Although the effects of jet lag vary among travelers, almost everyone experiences some change after air travel. Inherent differences in body condition among travelers determine varying strategies for jet lag management. These include good sleep, proper nutrition, and, sometimes, the use of medication.

Avoiding the factors that contribute to jet lag may be the best defense against it. Primary prevention means getting good sleep prior to a transmeridian flight. Since sleep-wake disturbance is the most widely felt effect of jet lag, being well rested before travel can only help the body cope with the inevitable change in time zone. This includes avoiding alcohol, caffeine, and nicotine, which are associated with restless sleep.

Furthermore, people have explored the use of melatonin as a remedy for jet lag. Melatonin is a hormone that is synthesized naturally by the pineal gland in the brain and is inhibited when the retina of the eye is exposed to light. Melatonin is also thought to influence circadian sleep-wake rhythms, because its effects on sleep-wake regulation are similar to those caused by exposure to light. Because melatonin is believed to impact circadian rhythm, taking melatonin at bedtime may advance one’s biological clock, that is, advance the body’s need for sleep.

Although travelers often claim benefit from its use, the use of melatonin has not been studied extensively and, at this time, is not largely recommended for jet lag therapy. Similarly, early morning bright light may advance a person’s sleep phase and allow them to go to sleep earlier. Travelers who arrive in sunny places may find it easier to adjust to a new bedtime.

Conversely, bright light in the evening can delay a person’s sleep phase and make it difficult for them to fall asleep at night. Therefore, depending on the contrasts between a traveler’s time zone and a new time zone, exposure and avoidance of bright light at certain times may help resynchronize one’s rhythm.

Sleeping pills (hypnotics) may be of limited benefit for the first two days following flight, especially if one needs a full night’s sleep to perform the next day. Short-acting hypnotics are generally recommended to avoid effects that carry over into the day hours. Over-the-counter medications typically have a lot of carry-over effects that can cause drowsiness and other significant problems for travelers who must perform. Physicians can advise travelers about what method of management is best for them.

Finally, travelers with sinus complications, who are extra-sensitive to the dry, pressurized, and noisy environment of an airplane, may find it beneficial to maintain hydration, proper nutrition, and proper sleep before flight. When the sinuses dry out and experience drastic pressure changes, they become irritated. Often, sinus-related symptoms occur with jet lag. In fact, some travelers claim their sinus problems cause the type of jet lag that they experience, which involves headache, earache, neck pain, congestion, and general grogginess. It may be beneficial for sinus sufferers to take a decongestant, as well as plenty of water, before traveling. Alcohol dehydrates the sinuses and tends to intensify the symptoms of sinus complications, so avoiding it may result in less severe sinus-related jet lag.

 

Sleep & Travelers

Whether you're a "Road Warrior" who has piled up thousands of Frequent Flier Miles, or someone who is planning a vacation to a distant location, you are likely to experience the phenomenon of "jet lag," which can have a profound effect on your sleep and alertness. This online brochure has some advice for travelers on what you can do now to help get a better night's sleep--when you arrive at your destination and when you return home.

 

JET LAG: THE TRAVELING SLEEP DISORDER

Every day, millions of travelers struggle against one of the most common sleep disorders—jet lag. For years, jet lag was considered merely a state of mind. Now, studies have shown that the condition actually results from an imbalance in our body's natural "biological clock" caused by traveling to different time zones. Basically, our bodies work on a 24-hour cycle called "circadian rhythms." These rhythms are measured by the distinct rise and fall of body temperature, plasma levels of certain hormones and other biological conditions. All of these are influenced by our exposure to sunlight and help determine when we sleep and when we wake.

When traveling to a new time zone, our circadian rhythms are slow to adjust and remain on their original biological schedule for several days. This results in our bodies telling us it is time to sleep, when it's actually the middle of the afternoon, or it makes us want to stay awake when it is late at night. This experience is known as jet lag.

 

TAKING THE AIR OUT OF JET LAG

 

Some simple behavioral adjustments before, during and after arrival at your destination can help minimize some of the side effects of jet lag.

• Select a flight that allows early evening arrival and stay up until 10 p.m. local time. (If you must sleep during the day, take a short nap in the early afternoon, but no longer than two hours. Set an alarm to be sure not to over sleep.)
• Anticipate the time change for trips by getting up and going to bed earlier several days prior to an eastward trip and later for a westward trip.
• Upon boarding the plane, change your watch to the destination time zone.
• Avoid alcohol or caffeine at least three to four hours before bedtime. Both act as "stimulants" and prevent sleep.
• Upon arrival at a destination, avoid heavy meals (a snack—not chocolate—is okay).
• Avoid any heavy exercise close to bedtime. (Light exercise earlier in the day is fine.)
• Bring earplugs and blindfolds to help dampen noise and block out unwanted light while sleeping.
• Try to get outside in the sunlight whenever possible. Daylight is a powerful stimulant for regulating the biological clock. (Staying indoors worsens jet lag.)
• Contrary to popular belief, the types of foods we eat have no effect on minimizing jet lag.

 

 

WORRYING ABOUT SLEEP

According to experts, stress or the potential for stress is another problem that can lead to sleeplessness. Two common travel related stress conditions are the "First Night Effect" and the "On-Call Effect." The first condition occurs when trying to sleep in a new or unfamiliar environment. The second is caused by the nagging worry that something just might wake you up, such as the possibility of a phone ringing, hallway noise or another disruption.

Try these tips on you next trip to help avoid travel-related stress and subsequent sleeplessness.

• Bring elements or objects from home like a picture of the family, favorite pillow, blanket or even a coffee mug) to ease the feeling of being in a new environment.
• Check with the hotel to see if voice mail services are available to guests. Then, whenever possible, have your calls handled by the service.
• Check your room for potential sleep disturbances that may be avoided; e.g., light shining through the drapes, unwanted in-room noise, etc.
• Request two wake-up calls in case you miss the first one.

 

QUIET PLEASE!

*The Sleep Environment*

The most common environmental elements affecting sleep are noise, sleep surface, temperature or climate, and altitude. Your age and gender also play a part in determining the level of sleep disturbance caused by these factors. One study found that women are more easily awakened than men by sonic booms and aircraft noise, while other research indicates that men may be more noise sensitive. Children are generally insensitive to extreme noise levels. However, this high threshold declines with age.

Noise

We have all experienced that dripping faucet, the barking dog or that blaring stereo next door that has kept us awake. Indeed, experts say the intensity, abruptness, regularity, intrusiveness, familiarity and regularity of noises all affect sleep.

Noises at levels as low as 40 decibels or as high as 70 decibels generally keep us awake. Interestingly, however, the absence of a familiar noise can also disrupt sleep. City dwellers may have trouble falling asleep without the familiar sounds of traffic. Or a traveler may find it difficult to sleep without the familiar tick, tick, tick of the alarm clock at home.

Some noises, although annoying at first, can gradually be ignored, allowing sleep to follow. Studies show people can get used to noises such as city traffic in about one week. However, important noises, like a parent's baby crying, a smoke alarm or even one's own name being called, are not easily assimilated and generally snap us awake.

Experts are also studying the ability of certain sounds to induce sleep. "White noise," such as caused by a fan, air conditioner, or radio static, can often block out unwanted noise and encourage sleep.

 

Sleep Surface

Little research is available and not surprisingly on how much sleeping surfaces affect our slumber. For the most part, we know people sleep better when horizontal and not cramped by space. As with noise, however, women and more mature people appear more sensitive to variations in sleep surfaces.

 

Temperature/Climate

The point at which sleep is disturbed due to temperature or climate conditions varies from person to person. Generally, temperatures above 75 degrees Fahrenheit and below 54 degrees will awaken people.

 

Altitudes

The higher the altitude, the greater the sleep disruption. Generally, sleep disturbance becomes greater at altitudes of 13,200 feet or more. The disturbance is thought to be caused by diminished oxygen levels and accompanying changes in respiration. Most people adjust to new altitudes in approximately two to three weeks.

 

SNOOZE CUES

 

Behavioral

Modifying your behavior and taking sleeping pills are both commonly accepted measures used to minimize certain sleep disorders.

As mentioned, certain behaviors can help your body better adjust to new time zones and surroundings. Although there are no guarantees to a fast and sound sleep, simple adjustments in your behavior when traveling may help you get the quality of rest needed to start the day refreshed.

 

Sleep Aids

According to NSF's 2002 Sleep in America poll, 15% of the respondents reported using either a prescription sleep medication (8%) and/ or an over- the- counter (OTC) sleep aid (10%) to help them sleep at least a few nights a month. While pills do not resolve the biological imbalance caused by jet lag, they may help manage short-term insomnia brought on by travel. Be sure to discuss the use of sleeping pills with your doctor before you try them. Sleep medication can cause side effects.

 

Melatonin

One OTC product receiving a lot of attention lately is melatonin. Melatonin is a naturally secreted hormone in humans that affects the body's circadian rhythms. There is some evidence that when administered during the day, melatonin increases the tendency to sleep, but at night, the amount of sleep is unaffected. Currently, melatonin is largely available only in health food stores and is not regulated. Therefore, melatonin is, at present, an experimental approach to sleep problems and travelers should consult their physicians before using it.

 

WHAT'S THE FUTURE OF SLEEP?

Although experts agree that a variety of analytical and anecdotal data exists about sleep, significant gaps still remain. Few definitive studies exist in the area of travel and sleep, making it impossible to know how prevalent travel-related areas of environmental and stress effects. NSF plans to expand its research and unravel more mysteries locked in the realm of sleep.

 

DON'T GO TO BED YET...

Since we spend a good portion of our lives sleeping, this self-quiz should be easy. Answer true or false to the following statements:

1. Jet lag can be controlled by carefully managing your dietary intake several hours before a flight.

2. "White noise," such as that caused by a fan or radio static, can block out noise and actually promote sleep in some cases.

3. According to sleep experts, pharmaceuticals are not an accepted method of sleep control and should be avoided.

4. Small amounts of alcohol prior to bedtime can be an effective way to induce sleep.

5. Due to the most recent research and studies regarding sleep, many of the mysteries surrounding that field have been solved.

Answers:

1. False. There is no conclusive evidence that diet can in any way minimize jet lag.

2. True. Studies indicate that "white noise" may help induce sleep.

3. False. Experts say, if taken as directed, sleeping medications can be an effective sleep manager. However, they have no effect on re-aligning the body's biological imbalance caused by traveling to a different time zone.

4. False. Although alcohol may initially cause sleepiness, later in the evening it acts as a "stimulant" and can keep you awake.

5. False. Scientists agree that more studies are needed to confirm what relatively little is known about sleep.

 

 

 

Overview

Jet lag, or desynchronosis, is a temporary condition that some people experience following air travel across several time zones in a short period of time. This causes the traveler's internal clock to be out of sync with the external environment. People experiencing jet lag have a difficult time maintaining their internal, routine sleep-wake pattern in their new location, because external stimuli, like sunshine and local timetables, dictate a different pattern. For this reason, one can feel lethargic one moment and excited the next. Jet lag creates a double bind for vacationers and business people who must cross several time zones to reach their destination, but who are also intent on maximizing sightseeing or productivity. As travelers attempt to adjust their internal clock to a new external environment, symptoms result with varying intensity.

Jet lag (desynchronosis) occurs while rapidly crossing time zones, or, more specifically, it occurs after crossing the Earth’s meridians. Meridians demarcate geographic position in relation to the Earth’s poles and, ultimately, define time zones. Jet lag is a unique sleep disorder because its onset is not necessarily caused by abnormal sleep patterns, like insomnia. Travelers who sleep normally prior to transmeridian travel are not immune to jet lag; the symptoms result when a person’s internal clock attempts to acclimate to a new external environment. This acclimation involves circadian rhythms that, among other functions, are associated with the body’s management of sleep.

Signs and Symptoms

In addition to the “tired-wired,” “soar-crash” feeling that travelers experience after long, rapid air travel, there are numerous symptoms that may occur with jet lag, such as insomnia, daytime fatigue, stomachaches, headaches, irritability, and decreased awareness. The degree of disruption varies greatly among people; some may not be bothered at all. Jet lag is a transient sleep disorder and is classified differently than other, more serious disorders. Although jet lag occasionally lasts for a week or more, travelers usually return to their normal sleep-wake pattern after a day or two.

For many travelers, jet lag can catalyze the effects of certain conditions associated with the head and nervous system that are not related to specific sleep-wake patterns. For example, many symptoms attributed to jet lag are actually caused by the environment of the airplane--dry air (humidity in an airplane is very low), pressurization, noise, vibrations, and a cramped environment. These symptoms may include dry eyes, dry and irritated nose and sinuses, headaches, earaches, muscle cramps, and abdominal distention (bloating). Occasionally, dizziness or swollen feet and ankles may occur.

 

According to the National Sleep Foundation’s Web Site

The basics of “jet lag” are that:

Anyone who has ever flown is likely to have experienced some degree of time zone change disorder, commonly known as jet lag. Until recently, jet lag was not treated as a medical condition. It is now included as one of the 84 known or suspected sleep disorders and affects millions of people each year.

Jet lag occurs when the body's biological clock is out of sync with local time. When traveling to a new time zone, our bodies are slow to adjust and remain on their original biological schedule for several days. The result is that we feel excessively sleepy during the day or wide awake at night.

People may experience jet lag in varying degrees. In general, the severity of jet lag symptoms is directly related to the number of time zones crossed by a flight. Jet lag symptoms typically last longer following eastward flights. Flying east usually results in difficulty initiating sleep, where as flying west results in early morning awakenings. All age groups are susceptible, but individuals over the age of 50 are more likely to develop jet lag than those under the age of 30. Also, individual susceptibility tends to vary considerably and it is possible that pre-existing sleep deprivation will intensify jet lag.

The Symptoms of jet lag include:

• Daytime sleepiness
• Nighttime alertness (insomnia)
• Loss of appetite and other
• Gastrointestinal dysfunction
• Mood disturbances
• Difficulty concentrating or focusing

Regarding Treatment, the site indicates that:

Researchers believe that gradually adjusting your bedtime to coincide with the time zone of your destination in the days before travel may prevent or reduce jet lag. On average, it takes about a day for each hour of time zone change to recover from jet lag.

In addition to adjusting your sleep schedule, prescription sleep aids may help reduce the amount of sleep lost as a result of jet lag. Over the counter sleep aids and alcohol should be avoided. Non-prescription sleep aids can cause sleepiness long after the intended sleep time and exacerbate the sleepiness associated with jet lag. Alcohol can disrupt sleep. Daytime sleepiness can be treated with caffeine, as long as it is not taken in the few hours before bedtime.

Melatonin, a naturally secreted hormone that regulates the body's internal clock, is used by some people to initiate sleep when traveling. Currently, melatonin is largely available only in health food stores and is not regulated. Therefore, melatonin is, at present, an experimental approach to sleep problems and travelers should consult their physicians before using it. Pregnant or breast feeding women and children should not take melatonin for jet lag. Melatonin (0.5mg) is probably only of use when traveling east. Travelers can take it a few days before, during or after traveling east and should take it ~5-7 hours before their usual bedtime in their old time zone. Melatonin can induce sleepiness so people should not drive or operate heavy machinery for several hours after ingestion.

On Coping with Jet Lag, the site inidcates that:

The following are additional steps you can take to minimize jet lag:

• Shift your sleep times before you travel. In the few days before traveling west, go to bed and wake up 1 hour later each day. In the few days before traveling east, go to bed and wake up 1 hour earlier each day.
• Regulate your light exposure before you travel. In the few days before traveling west, seek evening light and avoid morning light. In the few days before traveling east, seek morning light and avoid evening light. People can use a bright light box to get light, although people who experience migraines, mood disorders or have eye diseases should first consult with their physician before using one.
• Regulate your light exposure in your new time zone. If you traveled west, on arrival, seek morning light and avoid afternoon light. If you traveled east, on arrival seek evening light and avoid morning light. Weather conditions permitting, people can seek light by going outdoors and wearing only lightly tinted sunglasses. Do not look directly at the sun. Light can be avoided by staying indoors away from windows, wearing very dark sunglasses when outside and by sleeping.
• Avoid alcohol and caffeine for at least 3-6 hours before bedtime.
• Avoid heavy exercise close to bedtime.
• Bring earplugs and blindfolds to reduce noise and light while sleeping.

 

Another way to view what many call Jet Lag is what the researchers at Stanford call “The Time Zone Change Syndrome.” What is Time Zone Change Syndrome?

Time zone change (jet lag) syndrome consists of varying degrees of difficulties in initiating or maintaining sleep, excessive sleepiness, decrements in subjective daytime alertness and performance, and somatic symptoms (largely related to gastrointestinal function) following rapid travel across multiple time zones.

What are the symptoms?

The symptoms begin within 1 or 2 days after air travel across at least 2 time zones. A discernable disruption of the normal circadian sleep-wake cycle is present.

• Insomnia
• Excessive sleepiness
• Decreased daytime performance
• Tired muscles
• Headaches
• Moodiness
• Altered appetite
• Stomach problems
• Increase in the frequency of nocturnal awakening to urinate
• Generally feeling unwell

 

How can these symptoms be avoided when traveling?

It is important to adapt yourself to the routine of your destination as soon as you board your flight.

• Reset your watch for the new time zone
• Control sleeping, including naps, to optimize sleep at the appropriate time in your new locale. Many travelers go to bed immediately after arriving on an overnight flight. They usually fall asleep quickly but sleep a relatively short time, tending to awaken at a time corresponding to the late morning of their hometime. Then later that night they would have problems falling asleep because of their unadjusted circadian system which would be telling them that it is not time to sleep yet. To counteract this, it is better to limit your sleep to no more than 2 hours immediately after arrival.
• Eating foods that contain tryptophan (turkey, milk) can help induce sleep at the proper time at your destination. Some people even resort to taking small doses of hypnotics to produce sleep. Drugs such as temazepam (Restoril), brotizolam, and triazolam (Halcion) have been shown to produce high-quality sleep after extensive shifts in sleep schedules or after time zone transitions.
• Exposure to daylight can help reset your clock. Take a one-hour walk as soon as you get up.

Things to avoid that will slow down adaptation:

• long or inappropriate naps
• excessive caffeine
• social isolation
• poor sleep hygiene

British Airways has published information to help travelers deal with the problems of Jet Lag:

Jet lag
All air travelers want to arrive at their destination feeling rested and alert, but as air travel has become faster, the human body has found it increasingly difficult to keep up. Lack of sleep and disruption to the circadian clock (the brain's timekeeper) can lead to fatigue, digestive upset, and headaches. It can downgrade our decision-making by up to 50 per cent, communication skills by 30 per cent, memory by 20 per cent, and attention by 75 per cent.

British Airways doctors joined forces with Alertness Solutions to help business travelers and holidaymakers beat jet lag and sleep disruption. Alertness Solutions is a US consulting firm that translates scientific knowledge on sleep, circadian factors, alertness and performance into practical strategies that improve productivity and safety in our society. Visit Alertness Solutions(http://www.alertnesssolutions.com/Resources_Info/resources.html)

The information contained there includes web links to resources and publications. In addition, there are “exercises”:

How sleepy are you? Try these two sleepiness scales:

THE EPWORTH SLEEPINESS SCALE

How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired? This refers to your usual way of life in recent times. Even if you have not done some of these things recently try to work out how they would have affected you. Use the following scale to choose the most appropriate number for each situation:

SITUATION	CHANCE OF DOZING
Sitting and reading	____________
Watching TV	____________
Sitting inactive in a public place (e.g. a theater or a meeting)	____________
As a passenger in a car for an hour without a break	____________
Lying down to rest in the afternoon when circumstances permit	____________
Sitting and talking to someone	____________
Sitting quietly after a lunch without alcohol	____________
In a car, while stopped for a few minutes in traffic	____________

 

To check your sleepiness score, total the points . Check your total score to see how sleepy you are.

 

and the The Stanford Sleepiness Scale:

Stanford Sleepiness Scale   This is a quick way to assess how alert you are feeling. If it is during the day when you go about your business, ideally you would want a rating of a one. Take into account that most people have two peak times of alertness daily, at about 9 a.m. and 9 p.m. Alertness wanes to its lowest point at around 3 p.m.; after that it begins to build again. Rate your alertness at different times during the day. If you go below a three when you should be feeling alert, this is an indication that you have a serious sleep debt and you need more sleep. An Introspective Measure of Sleepiness The Stanford Sleepiness Scale (SSS) Degree of Sleepiness Scale Rating Feeling active, vital, alert, or wide awake 1 Functioning at high levels, but not at peak; able to concentrate 2 Awake, but relaxed; responsive but not fully alert 3 Somewhat foggy, let down 4 Foggy; losing interest in remaining awake; slowed down 5 Sleepy, woozy, fighting sleep; prefer to lie down 6 No longer fighting sleep, sleep onset soon; having dream-like thoughts 7 Asleep X

 

To ascertain “how is your sleep” they offer the sleep test from SleepNet:

http://www.sleepnet.com/sleeptest.html