Some people, however, experience a grogginess and lethargy that lasts much longer than the traditional twenty minutes and have a difficult time overcoming the feeling. This sleep inertia does not usually affect people unless they have jobs that require them to be extra alert and vigilant at all times such as driving a truck or just driving to work on a long commute. If you have sleep inertia that continually lasts longer than a few minutes, then you need to check it out and see what is causing you to be lethargic long beyond the norm.
It is well known that many accidents occur the first thing in the morning and that is because some people are not fully awake when they get behind the wheel of their vehicle. This can be very dangerous to you and to others because when you are not fully awake, your motor and cognitive functions are not working at their full capacity.
Some experience sleep inertia after a poor night’s sleep characterized by restlessness or inadequate amounts of restful sleep. If you are deeply asleep when you awaken, you can easily have a bout of sleep inertia because your body needs longer to fully come awake than normal. Some people just naturally are groggier in the morning because they like to stay up late at night and are more nocturnal than others who we might call “morning people.” These people almost never experience sleep inertia because they wake up raring to go and start the day with little thought that they need more sleep.
We don’t have to hate those “morning people” who are always so cheerful and ready to start the day when we take a little longer to adjust our bodies to wakefulness through our state of sleep inertia and ease gently into the day. A little sleep inertia is fine as long as it does not disrupt your day or cause you significant problems.