Why are people tired after over sleeping?

Answer by Nipun Sher:

Situation: You are so drowned in school or office work that you hardly get time to sleep on weekdays. You tell yourself that you will make up for the lack of sleep (sleep debt) on weekends. In fact, this promise of make-up sleep is one of the things that keeps you going. The much-awaited weekend comes and you try to “catch up” on lost sleep by sleeping longer hours, only to find out that you feel even more tired after waking up than sleeping in. Instead of feeling refreshed and rejuvenated, you feel sluggish and incapacitated.

I bet everyone has faced such a situation at one point of time or the other. So, what’s going on? And, why does it happen?


Big ol’ bum aka Body clock | Image Source: Lucid Communications

Basically, your body clock is a big ol’ bum. It has a penchant for following a regular routine (Circadian rhythm). When you oversleep, you mess up this routine. Big ol’ bum doesn’t like it and just goes bonkers. This results in a situation where your internal clock and body are not in sync. Due to this disruption in rhythm, your sleep cycle goes haywire and you end up feeling groggy and fatigued. This is very similar to how you feel when you are jet lagged.

Time for some definitions:

Sleep cycle: The sleep cycle lasts anywhere between 80-120 minutes, with the average being 90 minutes. Also, the average person has approximately 5 cycles every night, which amounts to a total of 7.5 hours.

Stages of Sleep Cycle | Image Source: Sleep Cycles. Sleep for Kids

Now, when you oversleep, you extend the number of sleep cycles. Generally, when you wake up, it is usually in the middle of a cycle. If it is during deep sleep or the REM stage of the cycle, you can end up feeling lethargic and spent. Additionally, the quality of sleep matters, too. If you spend more time in Stage 1 (lightest sleep), you will end up having a poor-quality sleep overall. As a result, you would try to compensate for the lack of quality with increased quantity, i.e., you will tend to oversleep.

Sleep debt: It is the deficit in sleep caused by the lack of enough sleep.
From Scientific American:

Sleep debt is the difference between the amount of sleep you should be getting and the amount you actually get.

Source: Can You Catch Up on Lost Sleep?

Sleep inertia: A body in sleep will want to stay in sleep unless an external force, such as Mom’s kick in the tush, is applied to it.

Jokes apart, sleep inertia may result in making you feel groggy after you’ve overslept. Here’s the definition from a research study on it:

Sleep inertia is the impaired cognitive performance immediately upon awakening, which decays over tens of minutes. This phenomenon has relevance to people who need to make important decisions soon after awakening, such as on-call emergency workers.

Source: Sleep inertia results in cognitive impairment

Oversleeping, it is believed, may cause you to experience sleep inertia more often. It is due to this, you feel the need to go back to sleep after waking up.
This state of sleep inertia, if severe enough, can also lead to a condition called sleep drunkenness or confused arousal.

Sleep drunkenness (SD) consists of difficulty in coming to complete wakefulness accompanied by confusion, disorientation, poor motor coordination, slowness, and repeated returns to sleep.

Source: Hypersomnia With Sleep Drunkenness

A study [1] published in the Neurology journal found that nearly 15% of us, or 1 in 7 people, suffer from sleep drunkenness. This “drunken stupor,” in severe cases, can also result in violent reactions and amnesia.

Oversleeping, if done once in a while, doesn’t result in any health risks; however, if you find yourself habitually oversleeping (Hypersomnia), it can cause serious health issues. A study done by Harvard [2] found that those who slept between 9-11 hours every night were more likely to develop a heart condition and/or develop some memory-related issues. Some other studies [3] have linked long-term oversleeping to diabetes, obesity, and even early death.

Other Factors

Even if you sleep regularly for 7-8 hours every night, you may still wake up feeling out of sorts and unrefreshed. This could be due to some underlying disorders:

Obstructive sleep apnea: It is one of the most common sleep disorders. It causes people to stop breathing momentarily while they are sleeping. It can also lead to an increased need for sleep, as it disrupts the normal sleep cycle. Even if you get sufficient amount of sleep, you may still wake up feeling tired, as the sleep you got was probably pretty light and crappy.
Read more about it here: Obstructive sleep apnea: MedlinePlus Medical Encyclopedia

Delayed sleep-phase disorder: People with this condition also tend to oversleep and wake up feeling groggy and tired.

Delayed sleep-phase disorder (DSPD), also known as delayed sleep-phase syndrome (DSPS) or delayed sleep-phase type (DSPT), is a circadian rhythm sleep disorder affecting the timing of sleep, peak period of alertness, the core body temperature rhythm, hormonal and other daily rhythms, compared to the general population and relative to societal requirements. People with DSPD generally fall asleep some hours after midnight and have difficulty waking up in the morning.

Source: Delayed sleep phase disorder

Furthermore, people with conditions like Hyperthyroidism, Narcolepsy, Depression (mood) also tend to oversleep, and thus, feel fatigued.

One thing I must mention that not everyone who oversleeps does so because of some underlying condition. Alcohol and some prescription drugs can also tend to cause people to oversleep.

Role of Genetics

We all have a friend who thrives even on little sleep. We also know people who need at least 9 hours of sleep to flourish. So, what the deal? Normally, people who sleep less than 6-6.5 hours a day are said to be short sleepers, whereas those who sleep more than 9.5 hours are considered long sleepers. Some studies have found that genetics also plays a big role in how much sleep one needs. A study [4] published in Science successfully identified a rare mutated gene, DEC2, in a mother-daughter pair that enabled them to function normally on 6 hours of sleep every night.

Personally, if I feel groggy after waking up, taking a 10-minute walk outside, or sitting in the balcony with the sun beating down on me tends to take care of it.

[1] “Sleep drunkenness” affects 1 in 7 Americans, study finds
[2] Too little sleep, and too much, affect memory – Harvard Health Blog
[3] Sleep Duration and Chronic Diseases among US Adults Age 45 Years and Older: Evidence From the 2010 Behavioral Risk Factor Surveillance System
[4] Rare Genetic Mutation Lets Some People Function with Less Sleep

Bonus: University of Michigan’s developed an app called Entrain to help people reset their body clock by logging the amount and type of light they get throughout the day. I have heard from a lot of people that it actually helped them a lot with their sleeping problems. For more details, go here: Reducing Jetlag through Mobile Tracking

AsapSCIENCE: How Much Sleep Do You Need?

Why are people tired after over sleeping?

thus, therefore and hence are different

A simple way of distinguishing and using these words accurately:

1. ‘Thus’ means ‘in this/that way’ – it relates to ‘HOW’ – the manner in which – this or that happens or comes about. It has a practical flavor.

For example,

Traditionally, you arrange things thus. = Traditionally, this is how you arrange things.

2 .’Therefore’ means ‘for this reason’, or ‘because of this or that’ – it relates to deductive reasoning, it tells WHY this or that is so, or happened.

For example,

He was late and therefore missed the bus. = he was late and for this reason missed the bus.

3. ‘Hence’ means ‘from this/that’ – it relates to WHERE – position, or point in time; it tells from where or what, or to where or what, something comes, derives, or goes.

For example,

i. Get thee hence! = Get yourself away from here!

ii. Henceforth all entrances will be guarded. = From now on all entrances will be guarded.

iii. She got the job – hence her good spirits. = She got the job and her good spirits derive from that fact. (Note the different slant to ‘therefore’, which would also fit, but would say ” her good spirits are due to (’because of’; ‘for that reason’) that”.


Ms. Office Word (2007, 2010, 2013): Typing Greek Letters and Math Symbol Quickly

When typing a document, especially the ones needing the Greek letters and some Math symbols, users would always look for the “insert symbol” function. This will take time to type and probably taking your hands away from the keyboard too. There is a working shortcut to insert these characters quickly into your document.

  1. Navigate to File menu in Office 2010/2013 (or the Office logo in Office 2007), on the top left of the screen, then click Options (or click Word Options in Office 2007).
  2. Go into the Proofing section, click the “AutoCorrect Options…” button.
  3. Go to Math AutoCorrect tab, check the “Use Math AutoCorrect rules outside of math regions” checkbox.
Word 2007 Options
Word 2010/2013 Options
Word 2010/2013 Options

After these steps been done, whenever we need to type a Greek letter, we could just type \omega and after pressing Spacebar, Word will automatically change that into ω character. If you need the capital, type \Omega and it will be replaced with Ω. Other than Greek letters, you can also insert Math symbol or any other symbol by typing its name like these examples:

  • \times is ×
  • \floor is 
  • \leftrightarrow is 
  • \Leftrightarrow is 
  • \ne is 
  • \degree is °

The complete list is available in Math AutoCorrect tab. Users can change them or add another shortcut according to their need.

Math AutoCorrect tab
Math AutoCorrect tab

Who You Are

From time to time, we read of people who are offended at not being treated with what they consider due respect and deference. “Do you know who I am?” they shout indignantly. And we are reminded of the statement, “If you have to tell people who you are, you probably really aren’t who you think you are.”

~David C. McCasland

People who demand respect is usually not the one deserving it. The one deserving it will get the respect according to his words and actions.

Engineer’s Clinic

An engineer was unemployed for such a long time. He couldn’t find a job and then decided to open a clinic and put a sign outside: “Get a treatment for your sickness by paying $100 fee, if not cured, you’ll get your money back in $200.”

A doctor read and felt this was a great chance to make some money and went into this engineer’s clinic.

Doctor: “I have lost my tasting sense in my mouth.”
Engineer: “Nurse, bring me medicines from cabinet 22 and put 3 drops of them in the patient’s mouth.”

The nurse did what the engineer told her and the doctor screamed.
Doctor: “This is gasoline!!”
Engineer: “Congratulations, you have your tasting sense back! The fee is $100.”
The doctor felt annoyed and returned again after a few days to gain back his money.

Doctor: “I have lost my memory, I don’t remember a thing.”
Engineer: “Nurse, bring me medicines from cabinet 22 and put 3 drops of them in the patient’s mouth.”
Doctor: “But that is gasoline!!”
Engineer: “Congratulations you have your memory back! The fee is $100.”

The doctor was angry and returned again after a few days by walking as a blind man.

Doctor: “I have lost my sight, my vision is very weak.”
Engineer: “Oooh, I don’t have cure for this. Go ahead and take this $200…” (but the engineer handed out only $100)
Doctor: “But this is only $100!!!”

Engineer: “Congratulations! Your sight has returned AND the price is $100!”

Enlighten Me Now Please

People think with their head and feel with their heart*.

*”heart” means their feeling not their literal heart organ.

I think these two English popular idioms would be problematic then:

  • Speak Up Your Mind
  • Only Do What Your Heart Tells You

If you speak whatever lies in your mind, then it’s not guaranteed that you’ll use your heart, you’ll only try to be rational without considering feelings. Then it’s normal for other people to get offended, isn’t it?

On the other hand, doing what your heart tells you means you’re doing mostly without thinking. Isn’t this another problem? Other people will also be in serious trouble or disagreement with you.

What do you think?

New Year Reflection

What is a new year eve,  especially on the 1st of January? It is basically a change of date based on convention, the only special about it is the date number. The actual day is no more than ordinary.

People celebrate it for refreshing times, specifically a year, when they can remotivate themselves to do some more accomplishments.

What is wrong with the refreshment “time”? Nothing, but it would only be wise to remotivate yourself whenever necessary not just at the first day of the year, not at the end of the year. Start doing everything necessary at any time of the year. Too many people wait for either the first time of the year or the last time of the year, it would only make them less motivated and mostly discouraged.

What is wrong with the celebration? What is celebration if you haven’t done many things worth celebrating at the end of the year?

Happy new year for those celebrating the event. And have a great motivation for better accomplishments this year, don’t wait for specific time, do it right away!