How Much Sleep Do You Really Need?

Even if you don't know exactly how many hours of sleep you need, you can sense when the numbers are off. You might feel sluggish, unfocused, or anxious. Other times, you might be getting so much sleep that you start wondering if it's possible to sleep too much. To clear up the confusion, we asked sleep experts how many hours of sleep adults need to feel their best. And based on their answers, the answer isn't as simple as you might anticipate.

The truth is, while doctors have similar baseline recommendations for how much sleep you should get, specific sleep needs vary from person to person. "Sleep need is like shoe size, there is no one size fits all," says Angela Holliday-Bell, MD, board-certified physician and founder of The Solution is Sleep LLC. Knowing about the factors that affect sleep can empower you to learn more about your own sleep needs, helping you feel as rested and energized as possible. If you slip up and sleep too much or too little, sleep experts also have ideas for correcting the course and getting back on track.

No matter where you are with your current sleep habits, the most important thing is making sleep a priority. If you're prone to wondering how many hours of sleep you need or your search history is full of queries like "is five hours of sleep enough," then working to upgrade your sleep behavior is a great first step in improving your overall health. Read on to see what sleep doctors had to say about the amount of sleep you should really be getting, plus what to consider when calculating your hours.

"People have probably heard the recommendation that they should be getting seven to eight hours of sleep," Dr. Holliday-Bell tells POPSUGAR, referring to the general guidelines set by the American Academy of Sleep Medicine. "But I would say that is an average number, meaning it will not pertain to everyone." Using herself as an example, Dr. Holliday-Bell says she needs about nine hours to feel fully rested. "I recommend that people find the number of hours of sleep they need to wake up feeling refreshed, fully energized, able to function optimally throughout their day without needing alertness boosters such as caffeine."

To find your perfect number, Dr. Holliday-Bell proposes a "sleep vacation" completely dedicated to rest and reset. No time restraints, no nighttime or early morning commitments, just a week to get to know your sleep cycle (sans melatonin and any other sleep medications). Dr. Holliday-Bell recommends taking five to seven days of vacation (at home or away) where you're completely unbothered and can wake up and sleep to a schedule dictated by only your body. Make sure to pick a space that doesn't trigger anxiety. This could mean a guest bedroom, a different area of the house, or a hotel room. The first few days are often spent working off any sleep debt. "After a few days, typically the body falls into the rhythm where you're falling asleep and waking up around the same time. Feeling refreshed, feeling good," says Dr. Holliday-Bell. Take note of that because that's likely how many hours your body is telling you it needs.

If a sleep vacation isn't possible — because let's be honest, taking a week to yourself isn't the most feasible recommendation for everyone — most experts suggest seven to nine hours of sleep for the average adult. Start from there and adjust your schedule accordingly.

There's a few things that can impact your sleep (how much of it you get and need), says Michael Breus, PhD, clinical psychologist and founder of The Sleep Doctor. Chief among them are age, gender, certain medical conditions, vitamin and mineral deficiencies, geographic location, caffeine and alcohol consumption, and socioeconomic status.

In general, teens (ages 13-17) need more sleep than adults, according to the CDC. Their baseline sleep needs might look closer to an eight to 10 hour range, while older adults (over 65) can sometimes operate on less sleep, with a seven to eight hour range, per the same guidelines.

Although it's still a topic of discussion, the Sleep Foundation reports that women may need more sleep than men. Research also shows women are significantly more likely to have insomnia, making it more difficult to sleep at night. Anyone experiencing hormonal changes may also see their sleep needs affected, as this can affect the body's circadian rhythm.

People with chronic illness may need more time to sleep, especially if they experience chronic fatigue. Good sleep can help the body recover, boost immunity, and manage inflammation, as per the National Gaucher Foundation. Poor sleeping habits are also thought to intensify mental illnesses like depression and anxiety, says Dr. Breus.

Where you fall on the socioeconomic scale may play an important role in how much sleep you get. A study published in Sleep Medicine journal surveyed over 150,000 participants across the US via telephone survey designed to measure their sleep complaints: "trouble falling asleep," "staying asleep," or "sleeping too much." Those of lower socioeconomic status were associated with higher rates of sleep complaints. To be more specific, lower income and educational attainment was associated with more sleep complaints. Additionally, employment was associated with less sleep complaints and unemployment with more.

According to research published in Sleep Health journal, certain regions of the Unites States, particular the Appalachia region experience disproportionately high amounts of insufficient sleep. This may be due to the fact that this region is also at greater risk for obesity, diabetes, and cardiovascular disease, among other health conditions, which are "also commonly identified as either risk factors for poor sleep or potential effects of poor sleep," per the Sleep Journal study. Those who live at higher altitudes have also been found to experience poorer quality of sleep, according to the Journal of Clinical Sleep Medicine.

It's no secret that your caffeine and alcohol habits can impact your sleep.

"It takes about two hours for a drink to completely metabolize, and during the process, you're not getting the deep sleep you should," Kent Smith, DDS, a dental sleep specialist and president of the American Sleep and Breathing Academy previously told POPSUGAR. "In addition, alcohol can also lead to frequent waking to get up and use the restroom and an increased risk for sleepwalking." Drinking alcohol can also throw off , leading to sleep disturbance and poorer sleep quality.

Consuming caffeine before bedtime can have a similar effect. Research out of the Journal of Clinical Sleep Medicine found that 400 mg of caffeine (the daily recommended intake, per the FDA) taken 0, 3, or even 6 hours prior to bedtime can significantly disrupt sleep.

Vitamin D deficiency has been linked to poor sleep quality and sleep disorders like insomnia and sleep apnea, per the National Institute of Health. Consequently, people with Vitamin D deficiencies may find themselves needing more sleep to feel refreshed, especially if they're working off sleep debt.

"It's called sleep deprivation and it affects humans in several ways," says Dr. Breus. You may experience physical repercussions like an elevated heart rate and blood pressure, emotional reactions like increased depression and anxiety, and cognitive consequences like decreased focus and poor memory.

Sleep helps maintain multiple systems in your body, from the heart to the immune system. It helps with proper hormone production, heart health, weight and metabolism, and even pain perception, Dr. Breus says. If you're not getting the right amount of sleep, you could be setting yourself up for long-term health issues that aren't as easy to sleep off.

When we don't get enough sleep, we aren't ourselves. Dr. Breus explains that short term sleep deprivation can worsen depression and anxiety, trigger hallucinations, and increase symptoms for those with bipolar disorder. By contrast, the American Psychological Association suggests that getting more sleep may actually help you feel happier.

Since sleep refreshes and regenerates brain cells, too few hours can make it harder for your neurons to function at the highest level, according to psychiatrists, Andy R. Eugene and Jolanta Masiak. Their research shows sleep turns off neurotransmitters, allowing for the proper production of norepinephrine, serotonin, and histamine. Without the right amount of sleep, it can be harder to concentrate, make good judgments, recall past information, and multitask the day following.

Over nine hours of sleep in a 24-hour window is technically considered excessive, but Dr. Holliday-Bell reminds us that there are plenty of legitimate reasons why some people may need more sleep. "Personally, I think it's hard to say that you can sleep too much and there are negative effects," she says, naming factors like chronic illness, sickness, and depression. She notes that if you're sleeping off "sleep debt" you may experience the grogginess of sleep inertia, which is different from the long-term consequences of excessive sleep. "I think the body does a good job of regulating what is needed based on your history and what actions you've taken in the past," says Dr. Holliday-Bell.

Apart from a sleep vacation, Dr. Breus says consistency is key. "Of all the sleep tips you could ever read or hear about, the most important one to follow is to stick to one consistent sleep schedule," he says. That means going to bed and waking up at the same time each day, even when you don't have a schedule holding you to it (like on a weekend). For all-around better sleep, Dr. Breus recommends moderate physical activity, cutting caffeine after 2 p.m., and refraining from alcohol three hours before bedtime.