Sleep debt is a serious concern for many people. It’s a deficit in quality sleep, and it can have serious health consequences. Chronic sleep debt is particularly bad for both mental and physical health.

Sleep debt is a useful term and measurement to determine whether or not you lose sleep too frequently. It is also helpful in describing how much you are undersleeping and how serious the problem is. For optimal health, learn how to avoid a sleep deficit and how to recover if you have it.

Sleep Debt Defined

Like monetary debt, sleep debt is a deficiency, and it has real and significant negative consequences for health. Sleep debt is the difference between how much sleep you should be getting at night and how much you actually got.

This is usually measured in hours and ranges in severity. For instance, a sleep debt of half an hour isn’t nearly as bad as a sleep debt of three hours.

Sleep Deprivation, Deficiency, and Debt – What’s the Difference?

These are all related and relevant terms useful when discussing sleep and health. Sleep debt is the number of hours, or a range of hours, of actual sleep missed. It can vary by night. For instance, you might have a sleep debt of two to three hours one night and just one to two the next.

Sleep deprivation is a term that describes any situation in which you don’t get enough sleep. You might be sleep deprived for one night because of significant sleep debt. You can also be sleep deprived for many nights in a row or even weeks and months if you really struggle with insomnia or another condition.

Sleep deficiency describes all the ways in which you can suffer from sleep issues. It includes sleep deprivation, but also getting poor quality sleep, having a sleep disorder, or sleeping at unusual hours, for instance, if you work a night shift.

How Much Sleep Do You Need Each Night?

Everyone is different and some people can get by on less sleep than others, but general guidelines for sufficient sleep apply to everyone. The range of amount of sleep needed varies by age in particular. According to the Centers for Disease Control and Prevention, these are the recommended number of hours of sleep per day by age:

• Newborns – 14 to 17 hours
• Infants (4 to 12 months) – 12 to 16 hours
• Toddlers (1 to 2 years) – 11 to 14 hours
• Preschool (3 to 5 years) – 10 to 13 hours
• Children (6 to 12 years) – 9 to 12 hours
• Teens (13 to 18 years) – 8 to 10 hours
• Adults – 7 to 9 hours
• Adults over 65 – 7 to 8 hours

Note that there is a range for every age group to account for individual differences. Sleep debt is never an exact number for this reason. If you should get seven to nine hours of sleep per night and only get five, your sleep debt is two to four hours.

The Consequences of Sleep Debt

Sleep debt is not ideal. In a perfect world, you would sleep enough hours every night to fit within your personal recommended range. Of course, this doesn’t always happen, and the consequences range from mild to severe.

One Night of Sleep Debt

A sleep deficit for one isolated night is normal for most people and doesn’t usually have long-term consequences. Still, one night of bad sleep does affect you during the day. It can make you moody, sleepy, and irritable. Poor sleep one day makes it difficult to concentrate or perform at work or school.

Just one night of inadequate sleep can potentially be serious if it causes an accident. Daytime sleepiness and slow reaction time can contribute to any type of accident, including car crashes.

Long-Term Health Consequences of Chronic Sleep Debt

Worse is a buildup of sleep debt. When you fail to get enough hours of sleep most nights for an extended period of time, you begin to put your health at risk. Some of the health problems associated with chronic sleep deprivation include:

• Cardiovascular issues, including high blood pressure, high cholesterol, and heart attack or stroke
• Weight gain, obesity, and type 2 diabetes
• Increased infections due to lowered immune system function
• More intense or frequent pain
• Degenerative brain conditions, like Alzheimer’s disease
• Mental health conditions, including depression and anxiety disorders

Having long-term sleep debt doesn’t ensure you’ll have these health problems, but it does increase the risk. If you have existing health conditions, long-term sleep deprivation can make them worse.

Additionally, all the issues that one night of bad sleep can cause are usually amplified by chronic sleep deprivation. Accidents and injuries are more likely, mood swings increase or are more severe, and performance suffers.

Can You Make up for Lost Sleep?

Yes, and no. It’s not a bad idea to bank extra sleep after losing sleep for a night or more. On the other hand, sleeping longer to pay off sleep debt is not a perfect solution. It might help after a night or two, but it is impossible to repair all the damage of insufficient sleep over long periods of time.

This means that a strategy of pulling late nights during the week and getting weekend recovery sleep is not a permanent solution to sleep debt. Even if you average seven hours of sleep per night in a week, you’ll suffer negative consequences if you don’t distribute the sleep evenly.

Recovering from Short-Term Sleep Debt

As a short-term solution, banking extra sleep whenever you can make a difference. For instance, if you have a bad night of sleep, a brief afternoon nap the next day might provide sufficient rest. It will refresh you and alleviate some of that daytime sleepiness and brain fog.

Studies have found that just one hour of sleep debt takes up to four days to repay. Consider the extra sleep you’ll need to get over the course of a week just to make up for one bad night.

If you do get stuck with a few nights of sleep debt, you can try to recover with naps and additional nighttime sleep. Be consistent each day with your bedtime, and give yourself a little extra time to sleep in the next day. Be patient, as it is likely to take more time than you think to recover from poor sleep.

You Can’t Fully Pay off Sleep Debt

Sleep research finds that incurring sleep debt and making up for it later does not reverse the harm done. One study looked specifically at weight gain. One of the many potential risks of getting too little sleep is obesity. Poor sleep changes hormones related to appetite and hunger, putting you at a greater risk of overeating, making poor food choices, and gaining weight.

The study of sleep debt and weight gain found that getting extra sleep on the weekend does not make up for the damage done to appetite. People who sleep too little during the week and pay off their debt on the weekend still have an elevated risk of obesity.

Another study found that when people had chronic sleep restrictions for ten nights in a row, it took more than a week of extra sleep to get back to normal cognitive functioning. Yes, extra sleep helps, but it cannot make up for getting enough sleep in the first place.

Prevention Is Best – How to Avoid Sleep Debt

Paying off sleep debt isn’t the best solution. It’s better never to accumulate that debt in the first place. Prevention is the best medicine, even when it comes to sleep. Avoiding sleep debt is all about making sleep a health priority. It’s as important as a good diet and regular exercise.

To stave off sleep debt, practice good sleep hygiene:

Be Consistent Every Single Day

The strategy of making up for sleep debt on the weekend is less than ideal. You can use it as needed, but don’t make it a habit. More useful is going to bed and waking up at consistent times, during the week, on weekends, and even on vacation. Keep a regular sleep schedule as much as you can.

Turn Bedtime into a Routine

One reason consistent bedtime and wake time helps is that it gets your brain and body used to a set schedule. Be consistent, and over time, you will begin to get sleepy at your normal bedtime. Falling asleep will get easier.

You can add to this effect by creating a standard routine. For instance, you might turn off the TV an hour before bed to read with a scented candle or to do a meditation. When it becomes a habit, the activity will signal your brain that it’s time to sleep.

Change Your Day to Sleep Better at Night

What you do during the day can hamper your sleep at night. Avoid caffeine in the afternoon. Limit or avoid alcohol in the evening. Don’t eat a heavy meal within a few hours of bedtime.

Exercise and light exposure during the day also affect your sleep at night. You need to be exposed to a certain amount of light for your sleep-related hormones to cycle correctly. Morning sunlight is best.

Also important is exercise. Be active every day, even if that means just taking a short walk. This will make you sleepier at night.

Optimize Your Sleep Environment

Take a critical look at your bedroom and make improvements so that it is more conducive to sleep. It should be dark and cool at night. Your bed, pillow, and linens should be comfortable but supportive.

Eliminate screens and avoid doing work in bed. If your room is cluttered and messy, it might stress you out. Clean and organize to put your mind at ease at night.

Use Sleep Tools

Any kind of relaxation aid or tool used at night can help you sleep better. For instance, guided meditation can help you bring anxiety and stress under control. Soothing sounds or white noise can relax you and drown out environmental noises that disrupt sleep.

See Your Doctor

If you struggle to sleep and continually get sleep debt despite your best efforts, you could have a sleep disorder like sleep apnea or another medical condition. Talk to your doctor. They can diagnose underlying conditions or refer you to a sleep specialist for evaluation and treatment.

Sleep debt is bad, but it’s also something you can change and control. Take steps to prevent sleep debt before it happens for the best results.

BetterSleep is your ally in this challenge. Find soothing sounds, music, and bedtime stories, and you'll fall asleep a little easier. You can also use the app to meditate for improvements to sleep over the long term. Anything you can do to avoid accumulating sleep debt will benefit your overall health.