What Is Sleep Debt and How Can You Overcome It?

Been more than a few nights since you've logged the recommended seven to nine hours of snooze time? Then you might be in debt — sleep debt, that is.

Neglecting to "pay" your body the rest it needs can leave you feeling worn out after just a day or two. And over time, it can raise your risk for serious health problems, experts say.

Here's everything you need to know about sleep debt, including how to catch up when you need to.

Sleep debt is sleep deprivation that has built up over many nights.

As a person falls short on sleep each night, the amount of sleep they need to catch up and feel rested — i.e., their sleep debt — increases, according to the Centers for Disease Control and Prevention (CDC).

"It's recommended that adults get eight hours of sleep per night. So if you were to only sleep for five hours a night, you'd be three hours short of the sleep you need," says Kunal Kumar, MD, medical director of the Sleep Center at Einstein Medical Center in Philadelphia.

"Do that for five nights in a row, and your sleep debt becomes 15 hours," Dr. Kumar adds.

As your sleep debt goes up and your body is "owed" more sleep, your energy reserves start to drop lower and lower. You'll start to feel so run down that even a night or two of snoozing longer (like sleeping in on the weekend) isn't enough to help you feel refreshed.

In order to get back to baseline, you'll need to "pay down" your debt incrementally, by regularly getting more sleep over an extended period of time, Dr. Kumar says.

We all know what it's like to fumble through the day after a night or two of lousy sleep. But when you've racked up a sleep debt, these effects can become amplified.

"You may have poor performance in school or at work and be at an increased risk for accidents," Dr. Kumar says.

Per the Cleveland Clinic, sleep debt can cause:

• Daytime sleepiness
  
• Fatigue
  
• Irritability
  
• Trouble thinking, focusing and remembering
  
• Slowed reaction times
  
• Headache
  

As sleep debt keeps building, it can start to take a more serious toll on your health. "Long-term sleep debt is linked to chronic health issues," Dr. Kumar says.

According to the Cleveland Clinic, people who consistently fall short on sleep are at higher risk for:

• High blood pressure
• High cholesterol
  
• Diabetes
  
• Poor immune function
  
• Increased sensitivity to pain
  
• Cognitive decline
  
• Depression
  
• Anxiety
  

Paying off sleep debt is similar to paying off monetary debt: You need to give back what's owed. In other words: Yes, you can catch up on sleep.

But only to a certain extent, says Angela Holliday-Bell, MD, a board-certified physician, certified sleep specialist and founder of The Solution Is Sleep. "While you can get more sleep to improve symptoms [of sleep deprivation], you can never fully recover the functions and processes that would have occurred on each individual night of sleep," she says.

That's why it's better to consistently get enough sleep each night, as opposed to skipping out on sleep during the week and then trying to "pay it back" over the weekend, she adds.

Of course, we all fall short sometimes. And when that happens, it's worthwhile to prioritize sleep in order to mitigate sleep deprivation's effects.

The good news is that, unlike financial debts, you don't actually have to repay your sleep debt hour for hour, Dr. Kumar says. Here are some tips he recommends:

In order to consistently get the amount of sleep you need, start going to bed earlier. For example, if you've been going to bed at midnight, try heading to bed an hour earlier, until you've trained yourself to feel tired around the new time.

After accruing a few days of sleep debt, "you sleep more deeply and usually recovery happens within a few nights after getting sufficient sleep," Dr. Kumar adds.

"If you're sleep-deprived for more than a few nights, then it may take longer to recover."

As for naps? They can give you a temporary boost and help you feel a little more alert. But short daytime snoozes don't deliver the same restorative benefits of nighttime sleep, so they're not effective at paying down sleep debt, per the National Heart, Lung, and Blood Institute (NHLBI).

If you're going to power nap, keep sessions brief — about 15 to 20 minutes. Napping for longer than that can actually make you groggy and make it harder for you to fall asleep at night, Dr. Kumar says.

Also, aim to nap before 3 p.m. — napping later in the day could interfere with your sleep drive at night, making it harder to drift off.

It's possible to avoid sleep debt with a few of these tips:

You can steer clear of sleep debt by getting the recommended seven to nine hours of sleep each night, Dr. Kumar says. That means going to bed and waking up around the same time each day.

Practicing good sleep hygiene can make it easier to nod off if you're having trouble falling asleep. Think: exercising regularly during the day, avoiding alcohol or caffeine at night, doing something relaxing before bed and putting away your electronic devices an hour or two before bedtime, per the Cleveland Clinic.

Remember, no one's perfect. It's fine to stay out late once in a while, and we've all had the odd night where it's tough to fall asleep or your sleep gets interrupted.

When that happens, "try to get a little more sleep on the subsequent day and then get back to your normal eight-hour regimen," Dr. Kumar says.

Try to stick to your same sleep schedule on the weekends, too. If you're consistently falling short on shut-eye during the week, a day or two of sleeping in may not be enough to help you catch up.

In fact, people who slept for five hours on weekdays and slept in on the weekends still experienced negative effects of sleep deprivation, including weight gain and reduced insulin sensitivity, according to a March 2019 study in ‌Current Biology‌.

Plus, oversleeping on the weekend can make it harder to fall asleep on Sunday night, setting you up for feeling tired on Monday morning, Dr. Kumar points out (a phenomenon sometimes referred to as "social jet lag.")

If you're not sleeping well due to sweating in your sleep, you could try a cooling mattress or cooling sheets to help you feel more comfortable.

You may also sleep poorly because of aches and pains. Try to layer a supportive mattress pad on top of your mattress, or use a memory-foam pillow to help reduce neck and back pain.

Sometimes sleep debt simply comes from poor sleep habits or staying up too late. Other times, it could be caused by an underlying sleep disorder like insomnia, sleep apnea or restless leg syndrome.

If your sleep debt is affecting your quality of life and you're not able to get more sleep on your own, let your doctor know, per the Cleveland Clinic. You may need to treat the underlying problem in order to get the rest you need.