The exact amount of sleep you need can change at various times in your life, but individual factors, such as general health and activity level, need to be taken into account as well. The Centers for Disease Control and Prevention (CDC) suggest that adults get at least 7 hours of sleep a night.

What causes a person to sleep a lot?

If you’re pulling all-nighters to finish a work project, or it’s exam time at school and you’re stressed, studying all night, and not sleeping, then it’s perfectly normal — healthy, even — to eventually crash and have couple nights of sleeping in.

Your body is trying to repair itself and get the rest it’s been denied. But if you’re regularly sleeping for long periods, it can be a symptom of something more serious.

Illness

When you start to feel sick, your natural instinct may be to hibernate and sleep. Researchers found evidence that this is beneficial.

In a study on fruit flies, researchers found that those who slept more after infection with bacteria had a higher survival rate than those who got less sleep. Flies who slept more also cleared the bacteria faster and more effectively than the flies who got less sleep.

This supports the idea that sleep helps to boost the immune response, and why it’s such a natural instinct to sleep more when coming down with an illness or fighting an illness.

Depression

Depression can affect how people sleep in different ways. Some people with depression have trouble sleeping, whereas others experiencing depression sleep too much. Sleep disturbances can also cause depression.

Individuals living with depression might have trouble staying asleep, which makes for nonrestorative sleep, hence the need to sleep more.

Other symptoms of depression include:

  • feelings of worthlessness
  • weight gain or loss
  • loss of concentration
  • slowed thinking

Talk to your doctor if you think you’re experiencing symptoms of depression.

Sleep apnea

Obstructive sleep apnea, or OSA, is the most common type of sleep apnea and can be a major factor in someone sleeping so much. It’s estimated that 25 million U.S adults have OSA.

OSA causes your breathing to pause while you’re asleep, usually for 10 to 20 seconds. This causes a very brief awakening that you won’t even notice. This is extremely disturbing to sleep cycles, and it can interfere with the restorative value of sleep, causing daytime sleepiness and an urge to sleep more.

Other symptoms of OSA are related to getting poor-quality sleep, such as:

  • drowsiness
  • forgetfulness
  • headaches

Talk to your doctor if you’re sleeping a lot, but experiencing symptoms of poor-quality sleep.

Narcolepsy

Narcolepsy is a rare disorder that causes “sleep attacks,” or a sudden onset of sleep, loss in muscle tone, and dreaming. People who are living with this condition often experience daytime sleepiness and can even fall asleep doing everyday activities.

Since the brain cannot control sleep-wake cycles, regular sleep cycles can get disturbed and cause excessive sleepiness. It’s thought that disruptions in the bodily chemical hypocretin are a cause of the condition, but autoimmune disorders and heredity can also play roles.

Talk to your doctor if you think you’re experiencing symptoms of narcolepsy.

Can sleeping too much cause health conditions?

Too much sleep is associated with a variety of factors, and while they might not be directly caused by an excess of sleep, there’s certainly an association between these ailments and sleeping too much:

Many of these complications have a reciprocal relationship with sleep. This means that too much sleep can exacerbate these illnesses, and the illnesses can exacerbate sleepiness.

That’s why it’s important to get to the root cause of the sleepiness, so that the more serious issue can be adequately addressed and treated.

The bottom line

There’s no doubt that getting enough sleep is a crucial part of a healthy lifestyle, but too much sleep can be a signal that there’s an underlying health issue. If you’re consistently sleeping more than 9 hours a night, or sleeping long amounts of time but not feeling rested, it’s a good idea to see your doctor.

Talk with them about your symptoms and sleep habits. Keep a sleep journal and any notes on how you’ve been feeling, and bring these notes with you to the doctor’s appointment. This information can be helpful to your healthcare provider.