Good morning, sleepy head! Oh, you didn’t get enough sleep last night? You’re feeling a little tired and foggy today? I’m yawning today too. And we’re certainly not alone. According to the Centers for Disease Control and Prevention (CDC), more than a third (35%) of U.S. adults report a lack of sleep (and that’s probably an underestimate).

And while compound interest can be a good thing when it comes to investments, it’s not so good when it comes to sleep. In fact, it doesn’t take long for our sleep debt to get out of control, and like a high-interest loan, that debt can be difficult to pay back.

What is Sleep Debt?

I’m so glad you asked. Sleep debt is simply the accumulation of the minutes (or, let’s be honest, hours) many of us skip out on regularly. It seems like there’s so much to fit into each day—work, family, exercise, cooking, cleaning, hobbies, education, errands, etc., etc.—and you can’t possibly get it all done without burning the candle at both ends.

Or, perhaps you have an ill child, spouse, or parent to care for and just don’t get enough time to rest yourself. Maybe your dog or cat woke you up in the middle of the night all week due to an upset stomach—or just because it’s hogging all the covers. Or, maybe the new season of Handmaid’s Tale (or whatever your favorite show is) came out, and you just had to watch one more episode. (It happens to the best of us…)

Yet, those lost minutes (and hours) of sleep can add up. Although it can vary from person to person, most adults need between 7 and 9 hours of sleep per night (not just time in bed), according to the National Sleep Foundation, and older adults need between 7 and 8 hours.

So, let’s say you know you need 8 solid hours of sleep to feel your best, yet this past week you only got 6 hours most nights. Heck, even if you got only 7 hours and 45 minutes, those minutes can add up, especially when it happens night after night.

What are the Symptoms of Sleep Debt?

Regardless, it doesn’t take long for the signs of sleep debt to start affecting you. Here are 13 symptoms of sleep debt:

• Feeling sleepy and fatigued during the day
• Lacking concentration and focus
• Having a hard time learning
• Being more forgetful
• Feeling less creative
• Experiencing more pain
• Performing poorly at your job
• Lacking motivation
• Feeling anxious, depressed, irritable, or moody
• Having a decreased ability to think positively
• Moving more clumsily or becoming accident prone (this includes behind the wheel of your car)
• Craving food, especially calorie-dense, highly palatable junk foods
• Experiencing a reduced sex drive

Worse, over time, a sleep dept can contribute to even bigger problems, including:

• Weight gain or difficulty with weight loss
• Decreased defense against infections
• Heart and respiratory issues/diseases including high blood pressure
• Increased risk of diabetes
• Decreased response to environmental cues
• Hallucinations (especially after a long stint of staying awake)
• Reduced quality of life
• Hormonal imbalances
• Increased risk of early death

What Causes Sleep Debt?

While many of us get knee-deep into sleep debt because we’re staying up too late or our sleep gets interrupted (e.g., from kids, pets, spouses, or unexpected noises), many folks just don’t get restful sleep due to more serious medical conditions like insomnia or sleep apnea. Others experience sleep disorders, circadian rhythm issues, or hormonal imbalances. Some chronic illnesses can also lead to a lack of sleep. Any of these can result in sleep debt and its daytime consequences.

Other surprising causes of sleep debt include:

• Consuming sugars at night, such as a sweet dessert or soda, can keep you up late well into the night.
• Likewise, heavy meals, particularly those higher in fat, late at night can make it harder to fall asleep as your body is busy with digestion.
• “Hidden” sources of caffeine or other stimulants, like dark chocolate or green tea, can make sleep elusive. Caffeine quite literally “blocks” sleep.
• Some folks take longer to metabolize caffeine, and it can remain in their systems for up to 15 hours. Experiment to find out if an afternoon coffee, tea, or soda is keeping you awake, and if so, replace it with a caffeine-free option (like water!) for a better night’s sleep.
• While it can feel blissful to catch a few extra hours of sleep on Saturday and/or Sunday morning, lazy weekends can upset your circadian rhythm, making it more challenging to fall asleep Sunday night.
• If you’re feeling a little crowded by your partner or pets, it can make it tough to nod off, especially if they toss and turn or snore. :-/
• If it’s too hot or too cold, you may find it challenging to stay asleep. If possible, keep your room temperature between 60 and 67 degrees for an optimal sleeping environment. If it’s too hot, you can try using a cool pillow to help lower body temperature, which helps facilitate sleep. If it’s too cold, wrap up your feet in warm socks to help heat up your body, drift off faster, and avoid a restless night of tossing and turning.
• While alcohol can often help people fall asleep, that nighttime cocktail can make it much more difficult to stay asleep. And even though it can help promote relaxation, too much alcohol actually prevents you from getting into deep sleep. In other words, you might pass out, but you’re less likely to get restful sleep.
• Lack of regular exercise and physical activity can also make it harder to fall asleep. It can take some time before you notice improved sleep (from two to four months), but regular exercise can help people sleep longer and boost daytime energy levels.
• After a long, hard week, you probably feel exhausted, but also, you’re stressed out. Because you’re under stress, that exhaustion may not help you sleep. In fact, you may feel like you’re on high alert instead—the ol’ “tired but wired” paradox. Take some time to decompress, meditate, breathe, or stretch to help relax before climbing between the sheets.
• Until the last minute of each day, many of us are on our devices, which emit high-energy blue light. Whether you’re catching up on texts and emails or watching funny cat videos, that blue light can negatively affect your sleep cycle by telling your body it’s time to stay awake—even if it’s after 11:00 pm.

Now that you know why you’re accumulating sleep debt, what can you do about it?

How Can I Recover My Sleep?

Here’s the good news: You can pay down your sleep debt fairly quickly and easily, especially if you’ve only missed a few hours of good sleep. (Admittedly, it does become much more difficult to catch up if you’ve been burning the candle on both ends for years.)

How?

Get more sleep! To pay back your most recent sleep debt, start by going to bed an extra hour earlier. For example, if you typically need a solid 8 hours to wake up feeling refreshed and rearing to go throughout the day yet you’ve only been getting 7 hours, set aside 9 hours to sleep to begin paying back your sleep debt.

If you’re only short a night or two, you’ll catch up in no time. On the other hand, if you’ve only slept 5 or 6 hours per night for the last week or so, it might take more time to catch up. Either way, you’ll likely start feeling better within days of getting that extra sleep. And once you feel like you’ve caught up, you can go back to your regular sleep schedule knowing you’re keeping your sleep account balanced.

To both pay off your sleep debt and prevent excessive withdrawals in the future, start improving your sleep hygiene. Here’s how:

• Go to bed earlier when you’re tired rather than pushing your limits and forcing yourself to stay awake to finish one last thing or enjoy one more show.
• Keep your bed- and wake-up times consistent, even on the weekends, and create a bedtime ritual to help you relax.
• Eat your last meal at least 2 – 3 hours before you go to bed and adjust your food choices to avoid blood sugar spikes/crashes, digestive discomfort, etc.
• Avoid consuming caffeine and other stimulants after 2:00pm.
• Exercise regularly, and if you have a hard time sleeping, exercise in the morning or early in the afternoon rather than in the evening.
• Keep the temperature in your bedroom between 60 and 67 degrees.
• Keep your bedroom dark and quiet (white noise can be helpful).
• Avoid blue light-emitting electronic devices an hour or so before you go to bed. You can take it one step further and completely turn off devices and even your router at night to prevent EMF (aka dirty electricity) disturbances.
• Try napping—just not too long or too close to bedtime. You can grab a 20-minute power nap or a longer nap, up to an hour and a half. More than that, and you may not be able to sleep at night, defeating the purpose.
• Increase the amount of time you spend in natural light during the day. In particular, spend some time outside within the first hour or so of waking.
• Manage stress levels.

Luckily, just one night of a really good night’s sleep can help you start feeling so much better. You’ll find that your mind and mood are able to recover quickly. Believe it or not, those who are older tend to be both more resilient against sleep debt and to rebound more quickly than their younger counterparts (like kids and teenagers).

Once you’ve caught up, focus on healthy sleep hygiene and keeping your circadian rhythm in check to remain (sleep) debt-free.