Too much sleep — as well as not enough sleep — raises the risk of chronic diseases, such as coronary heart disease, diabetes, anxiety and obesity in adults age 45 and older. Sleeping too much puts you at greater risk of coronary heart disease, stroke and diabetes than sleeping too little.
How Much Sleep Is Too Much? Sleep needs can vary from person to person, but in general, experts recommend that healthy adults get an average of 7 to 9 hours per night of shuteye. If you regularly need more than 8 or 9 hours of sleep per night to feel rested, it might be a sign of an underlying problem, Polotsky says.
Research bears out the connection between too much sleep and too little energy. It appears that any significant deviation from normal sleep patterns can upset the body's rhythms and increase daytime fatigue.
“About 2 percent of the population are 'long sleepers' who require between 10 to 12 hours of sleep nightly on a regular basis,” says Shanon Makekau, MD, the chief of pulmonology and the sleep medicine director at Kaiser Permanente in Honolulu. For these people, oversleeping is normal.
Hypersomnia is a condition in which people have excessive daytime sleepiness. This means they feel tired during the day. Hypersomnia can also include situations in which a person needs to sleep a lot. This may be due to other medical conditions, but can also be due to a problem in the brain.
In medical terms, oversleeping means sleeping more than nine hours in 24 hours. It's associated with a higher risk of several conditions, including heart disease, stroke, and heart failure. That doesn't mean it causes those conditions. Instead, oversleeping may be a symptom of other underlying conditions.
It's true a good night's sleep is essential for health. But oversleeping has been linked to a host of medical problems, including diabetes, heart disease, and increased risk of death.
Scientists believe that the pacemaker evolved to tell the cells in our bodies how to regulate their energy on a daily basis. When you sleep too much, you're throwing off that biological clock, and it starts telling the cells a different story than what they're actually experiencing, inducing a sense of fatigue.
Sleep hygiene practices
not having a regular bedtime routine, which includes consistent sleep and wake times. taking long daytime naps. looking at phone or computer screens before going to bed. having a sleeping environment that is too hot, too bright, or too loud.
Research suggests there's a link between too much sleep and weight gain. As with too little sleep, there is a greater risk of obesity among people who sleep too much. The risks and problems associated with oversleeping go well beyond weight gain.
Oversleeping feels so much like a hangover that scientists call it sleep drunkenness.
Sleep feels good because when we rest, our bodies produce melatonin, which controls our sleep patterns. Our melatonin levels increase at bedtime, making us feel tired. Melatonin, secreted by the pineal gland, makes us feel cozy and relaxed, allowing our bodies to get the time off they need at the end of each day.
The “right” amount of sleep proves somewhat individual as some people will feel great on seven hours and others may need a little longer. However, in most studies and for most experts, over nine hours is considered an excessive or long amount of sleep for adults.
Most likely, you're still tired after 8 hours of sleep because you don't know your sleep need, you're getting less sleep than you think, you've got sleep debt, or you're out of sync with your circadian rhythm.
It's called sleep inertia: "The transitional state between sleep and wake, marked by impaired performance … and a desire to return to sleep." The main thing to know about sleep inertia is it is completely normal.
Sleep inertia, or wake-up grogginess, is the main reason you're unable to fully wake up in the morning or after a nap. It's a completely normal part of your sleep-wake cycle that's intensified by factors like high sleep debt and circadian misalignment (caused by sleeping in, social jetlag, and travel jet lag).
Hypersomnia and Excessive Sleepiness
It can happen because of illnesses like epilepsy or Parkinson's disease, or mental conditions like depression. It's also the main symptom of narcolepsy and of a condition called Kleine-Levin syndrome. Certain medications, as well as alcohol and drug abuse, can cause it as well.
“There is no such thing as a “fixed or ideal time” to go to bed which will suit all individuals. It is generally advisable to fall asleep between 10 pm to midnight as for most people this is when the circadian rhythm is at a point that favours falling asleep.”
Sleep and Aging
Older adults need about the same amount of sleep as all adults—7 to 9 hours each night. But, older people tend to go to sleep earlier and get up earlier than they did when they were younger. There are many reasons why older people may not get enough sleep at night.