Chances are good that you need more sleep. According to the CDC, around one in three American adults get less than seven hours of sleep per night. And trying to catch up on the weekends may not be enough. Just one hour of sleep deprivation1 takes up to four days of optimal sleep to bounce back from.
Even more concerning, it all adds up. Sleep debt refers to the slow accrual of sleep deprivation that happens over time. But, how bad is sleep debt, and how do you "repay" it? Let's dive into the science of sleep.
What is sleep debt?
Think of your body like a bank, and each night you're depositing a set amount of money into it. If you miss your "payment" one night, you'll owe more money the next night to make up for it. Sleep deprivation accumulates in this way. "Sleep is indeed like a bank account, and each night one gets less than the recommended amount counts as a draw on the funds," explains Alex Dimitriu, M.D., a double board-certified doctor specializing in psychiatry and sleep medicine. "For someone well rested, missing one hour of sleep on one night often has quite a minimal impact. Over time, however, the missed hours begin to add up."
The more sleep-deprived you are, the more serious the health effects can become.
Acute sleep deprivation is what happens when you get significantly less sleep one night—say you pulled an all-nighter to work or study.
Chronic sleep deprivation occurs when you get less than ideal sleep over an extended period of time. Perhaps you slept six and a half hours every night for a month. You may not notice the effects after one day, but over time, you'll start to experience symptoms consistent with long-term sleep deprivation.
Unfortunately, recovery is not as simple as "miss one hour of sleep, get an extra hour the next night." So, it’s best to start adjusting your sleep habits ASAP to counteract any damage you might be doing to your health.
What are the health impacts of a sleep deficit?
Besides making you feel irritable and groggy, sleep deprivation can have seriously negative impacts on your ability to function. People who sleep less than seven to nine hours per night experience problems with alertness, attention span, and focus, and some studies have shown that sleep deprivation has long-term effects on memory and brain function2.
"Our brain and the body's physiology requires sleep to function well and properly," Eva Selhub, M.D., tells mbg. "It is during sleep that your body recovers and the immune system works to heal anything that requires fixing. Without sleep, the physiological balance and regulation is off, which will lead to not only short-term problems of fatigue, making mistakes, problem-solving issues, irritability or more mood changes, but long-term problems, like increased inflammation, changes in the circadian rhythm, increased activation of the stress response system, mood disorders and emotional distress, somatic pain, memory problems, and poor cognitive functioning and performance."
The extent of these effects differs from person to person. Some people naturally require less sleep than others to function well. There's no clearly defined scientific explanation for this, but a 2014 study in the Science Translational Medicine journal found that nightly sleep requirements vary based on a person's DNA.
How to recover from a sleep deficit.
There are things you can do to improve your sleep and make up for lost time. The sooner you implement these strategies in your life, the more you can mitigate any negative repercussions from acute or chronic sleep deprivation.
Short-term sleep fixes.
After a rough night when you didn't sleep as much as you'd intended, there are a few things you can do to make the next day a little better. "If your schedule does not allow you to actually spend more time in bed sleeping, you can take a 20-minute nap during the day and try to catch up on the weekends by sleeping longer by a couple of hours," explains Selhub.
Try to go to bed earlier the next night if you're able to. But don't feel the need to crash for 12 straight hours—you don't want to mess up your sleep schedule so much that you're unable to get back in a consistent routine.
Long-term sleep fixes.
This is where great sleep hygiene comes in handy. "Sleep really does well with rhythm," Dimitriu says. He recommends setting regular bedtime and waking times for yourself, avoiding alcohol and caffeine before bed, and getting treated for any pain or sleep apnea that may be waking you up during the night.
"Ideally, set up a routine to allow an eight-hour window for sleep each night," Dimitriu advises. "This is helped by doing quiet, relaxing, and even boring things in the hour before you intend to fall asleep."
Rather than watching three episodes of Love Island before you hit the sack, cap it at one episode and then pick up a book instead. Try to avoid screens with blue light that might disrupt your melatonin levels4 before you go to bed. A cool room helps your body temperature drop more quickly (something your body naturally does to prepare for sleep5), so crank up that fan or A/C to create an optimal nighttime environment for yourself.
If you love to exercise at night, try moving your daily workout to the morning hours and see if it improves your sleep. Some people do just fine with evening workouts6, but everybody is different. You may feel too energized after a sweat session to climb straight into bed, and your sleep could suffer as a result.
Sleepless nights are no fun, and over time, they can wreak havoc on your ability to live a happy and productive life. As you start accruing sleep debt, you'll notice problems with focus, memory, and brain function—things you really don't want to sacrifice.
If you've tried every solution and still can't sleep, talk with your doctor to figure out the best game plan for you. No one person responds to sleep triggers the same way. The sooner you can figure out exactly what's keeping you up at night, the sooner you can get that much-needed rest your body deserves.
Sarah Ellis is a lifestyle and wellness writer, as well as the co-host and producer of society and culture podcast, Subtext. She received her bachelor's degree from Belmont University and a Master of Arts in Journalism at New York University. Sarah covers the intersection of wellness, feminism, and pop culture and has previously written for Elite Daily, Greatist, and Rewire.News. She has also been featured on WNYC's Midday Show for her investigative reporting on male birth control research.