How Much Sleep Is Too Much Sleep? Here Are the Symptoms of Oversleeping

Sleeping in to recover from lack of sleep is great, but when does it become oversleeping?

Person oversleeping on the couch

Finding reasons to sleep more is easy, especially if your energy level is hovering around 3 out of 10. But if 10 also represents the hours of sleep you’ve been needing every night, and you still feel fatigued after sleeping all day to recovery, then there could be a different issue at hand: oversleeping.

Are you sleeping in, or are you oversleeping? When is a 9-plus hour sleep session a sign of an underlying health or lifestyle problem? Read on for a quick primer on oversleeping.

What is oversleeping?

Oversleeping is when you sleep for more than 9 hours within a 24-hour period. While there may be times when getting more shut-eye is needed — like after burning the midnight oil for a project, or when you’re recovering from a cold or flu — oversleeping can also be a sign of other health issues.

In some cases, oversleeping can become a disorder known as hypersomnia. People with this condition may experience symptoms, such as:

  • feeling drowsy during the day
  • headaches
  • excessive napping
  • anxiety
  • memory impairment

When doctors can’t pinpoint the cause of your oversleeping, it falls under the umbrella of idiopathic hypersomnia (IH).
However, it’s rare for oversleeping to happen without a known cause — and knowing what that is could help you find the right solution. The answer to oversleeping isn’t just sleeping less.

Why are you sleeping so much?

If you’ve only been oversleeping for a few days and have no other symptoms, you could be trying to make up sleep debt. However, the majority of people who sleep too much do so because of an underlying health problem, explains Dr. Aneesa M. Das, a sleep-medicine specialist at Ohio State University.

If you’ve been oversleeping and are still feeling tired even after a 9-hour sleep session, it might be time to explore these common causes of oversleeping.

1. Frequently wake-ups throughout the night

Every time you wake up in the middle of a sleep stage, you lose out on the restoration your body was seeking. What causes you to wake up can be external (think: noises, light, and children) or internal, such as sleep apnea and insomnia. When these wake-ups become too frequent, they can cause your need for 7 to 9 hours of sleep to extend over 10 hours.

2. Health conditions that cause exhaustion and fatigue

Living with health conditions can be exhausting, especially when they lower your sleep quality at night. Conditions linked to excessive sleep include:

Delayed sleep phase syndrome and narcolepsy can trigger excessive sleepiness by interfering with your body’s natural sleep-wake patterns, Das says. Although less common, Parkinson’s disease and myotonic dystrophy can cause hypersomnia.

In extremely rare cases, excessive sleep can be a symptom of Kleine-Levin syndrome, a disorder characterized by recurring episodes of excessive sleep up to 20 hours per day, according to the National Institutes of Health. These episodes can last anywhere from a few days to weeks at a time, occur most commonly in adolescent males, and can accompany flu-like symptoms.

3. Frequent depression and anxiety

A near-universal symptom of depression, extreme fatigue can encourage sleep times to run long. What’s more, many people experiencing depression or anxiety commonly use sleep as an avoidance mechanism, says clinical psychologist Michael J. Breus, Ph.D., a fellow of the American Academy of Sleep Medicine.

“When people tell me that they are sleeping 10 hours per day, my first concern is depression,” Breus says. Each year in the United States, more than 7% of adults experience a major depressive disorder, according to the National Institute of Mental Health.

If you suspect you could be experiencing depression or any mental health condition, talk to your primary care physician, psychologist, or psychiatrist for the medical attention the condition warrants, he says. For people whose hypersomnia is related to depression, cognitive behavioral therapy for insomnia can be a helpful way to improve sleep quality.

4. Chronic sleep deprivation

“The majority of Americans are getting too little sleep, so when given the opportunity, they sleep longer than the recommended 7 to 9 hours,” notes Das. While the occasional catch-up is OK, the goal is to avoid rollercoaster sleep schedules, she says.

If you find yourself sleeping more than usual, it’s also worth considering if your “usual” is less than the recommended 7 to 9 hours per night. You may be in a state of sleep deprivation and not know it. In that case, sticking to a consistent sleep schedule, rather than sleeping in, may be a more productive solution.

5. Idiopathic hypersomnia

Oversleeping as its own condition without an underlying health problem is known as idiopathic hypersomnia. IH is characterized by:

  • sleeping for more than 12 hours  
  • not feeling restored after more than 12 hours of sleep or a nap 
  • difficulty waking  
  • sleep drunkenness, or a condition where you suddenly wake up feeling confused, go back to sleep, and wake up again  
  • brain fog and feelings of “mind blankness”  

The condition is different from narcolepsy, which is neurological, because people with IH can power through their fatigue and stay awake.

Is too much sleep bad? Here are the risks and side effects

Quality sleep has positive effects on your mind and body. Sleeping too much, however, can have the opposite effect.

1. Lower quality of life

The most immediate impact of sleeping too much is on your quality of life. By spending 10 to 12 hours per day snoozing, you lose time you could devote to activities outside of your immediate priorities.

You may have less time for hobbies, exercise, and meaningful relationships, and research has long documented the positive health benefits of both social connections and physical activity.

2. Decreased immune function, memory, and energy

It’s easy to assume that too much sleep is the problem. But according to Johns Hopkins, poor energy, memory, and function may be due to the same underlying health and lifestyle factors that cause excessive sleep.

If you’re oversleeping because you wake up in the middle of the night, these sleep disruptors are likely also interrupting your sleep stages. Depending on which sleep stage is interrupted, your body and brain may not have gotten the restoration time they needed to repair your muscles or consolidate your memories.

3. Increased risk of mental health conditions and higher BMI

Previous studies have associated sleeping too much with the risks of diabetes, being overweight, heart disease, and more. However, a large 2014 review that redefined too much sleep as over 10 hours found that oversleeping is mostly associated with increased chance of depression and a higher BMI.

How to manage and treat oversleeping

Before jumping to any self-diagnoses, take a deep breath. If you don’t have any conditions that may be disrupting your sleep or causing you to feel excessively sleepy, you may first want to reset your sleep hygiene before making a doctor’s appointment.

Mother and daughter stretching at home
Photo by Ketut Subiyanto from Pexels

Here are some simple habits to adopt for better sleep:

  • Stop trying to “collect” sleep hours ahead of time. The best way to plan ahead is by shifting your sleep schedule, gradually, so that you can be awake when you need to be.  
  • Establish a consistent sleep and wake time. Sleeping and waking at the same time helps keep your circadian rhythm in check. Stick to this schedule even on the weekends so you don’t end up suffering on the weekdays.  
  • Have a regular exercise routine. Exercising in the morning can help increase your energy during the day and tire you out by bedtime.  
  • Avoid caffeine eight hours before bed and alcohol completely, if possible. Caffeine can throw off your bedtime by keeping you up. Alcohol, a depressant, can make you sleepier for longer. 
  • Skip naps, if possible. If you need a nap, take it earlier in the day so you aren’t wired at night.  

Don’t be discouraged if you don’t immediately start sleeping the “normal” number of hours. First, everyone has a different number. While 7 hours might be enough for your partner, it doesn’t mean it’s enough for you, Das says. It also takes time for your body to adapt to new sleep habits. You might need to experiment with multiple relaxation techniques before feeling ready for bed becomes a natural routine.

When to see a doctor

If you suspect an underlying condition is affecting your sleep quality, schedule an appointment to address your sleep concerns with your primary care physician, says Breus, noting that habitually sleeping 9.5 hours or more is nothing to shrug off.

In the days or weeks leading up to your appointment, keep a sleep journal to track:

  • what time you go to bed each night and what time you wake up 
  • how fast you fall asleep   
  • how well-rested you feel in the morning 

Also note the factors that could be affecting your sleep — such as mental or emotional stressors, physical activity levels, or any medication usage — and describe your quality of your sleep. You might notice yourself logging extra hours after, or during, nights when you wake up frequently.

This journal will give you and your physician a great place to start in determining what’s going on and your next best steps for restorative sleep.