It is normal for people to feel sleepy from time to time, particularly after a long day. However, excessive sleepiness can be disruptive and make it difficult for a person to go about their normal daily activities.
Some of the more common causes of excessive sleepiness include not sleeping long enough and having poor quality sleep.
In some cases, excessive sleepiness may be due to a sleep disorder or another underlying health condition.
Read on to learn about the various causes of excessive sleepiness, along with their symptoms and treatment options.
Excessive sleepiness can be difficult to quantify, as it may mean different things to different people.
In general, it is a feeling of fatigue or sleepiness that lasts throughout the day or for many days.
Excessive sleepiness is a relatively common issue. A 2019 study in Nature Communications notes that 10–20% of people deal with excessive sleepiness to some degree.
There are several possible causes of excessive sleepiness, each of which has different treatments.
Sleep deprivation occurs when a person does not get enough sleep. The American Academy of Sleep Medicine (AASM) note that adults need between 7 and 8 hours of sleep each night to feel alert and well-rested the following day.
However, according to the AASM, about 20% of adults fail to get enough sleep.
A person who does not get enough sleep during the night is likely to experience excessive sleepiness the next day. People who regularly fail to get enough sleep may feel constantly tired.
Some common causes of sleep deprivation include:
- excessive or inconsistent work hours
- personal obligations
- an underlying medical condition
Underlying medical causes require their own specific treatments. In most other cases, simple lifestyle changes can usually improve the duration and quality of a person’s sleep.
Insomnia is a sleep condition in which people have difficulty sleeping. People who have insomnia tend to feel excessively sleepy but are unable to fall or stay asleep.
People may experience insomnia in different ways. Some common symptoms include:
- being unable to get to sleep
- waking continually throughout the night
- waking very early in the morning and being unable to fall back to sleep
Insomnia can be difficult to diagnose. The Centers for Disease Control and Prevention (CDC) note that doctors generally only diagnose insomnia by ruling out other potential sleep disorders.
Treatment for insomnia may involve a combination of therapies. Examples include:
- sedative-hypnotic medications
- behavioral techniques to promote regular sleep
Obstructive sleep apnea
Sleep apnea is a disorder in which a person temporarily stops breathing during sleep. It is a relatively common cause of excessive daytime sleepiness.
There are two types of sleep apnea:
- Obstructive sleep apnea (OSA): OSA occurs when the soft tissues in the back of the throat collapse, blocking the airflow.
- Central sleep apnea (CSA): CSA occurs when the brain fails to signal to the respiratory muscles to breathe.
Some people experience mixed sleep apnea, which is a combination of OSA and CSA.
Episodes of sleep apnea may occur dozens or even hundreds of times in a single night. As a result, they can greatly disturb a person’s sleep cycle.
Common symptoms of sleep apnea include very loud snoring and gasping for air throughout the night.
During an episode of sleep apnea, a person’s body becomes temporarily starved of oxygen. This lack of oxygen may lead to other issues, such as an irregular heartbeat. Over time, this can lead to serious chronic conditions, such as high blood pressure and heart disease.
Sleep apnea commonly occurs when a person is overweight. When this is the case, weight loss will be the first recommended treatment.
Two common treatments for sleep apnea include:
- Positive airway pressure devices: These devices consist of a machine that attaches to a mask, which the person wears over their face. The machine supplies pressurized air into a person’s throat while they sleep. The air prevents the throat from collapsing.
- Oral appliances: These are similar to a mouthguard or orthodontic appliance. The devices hold the lower jaw forward slightly during sleep. This positioning prevents the soft tissues in the back of the throat from collapsing and blocking the airways.
Restless legs syndrome
Restless legs syndrome (RLS) refers to an uncontrollable urge to move the legs when they are at rest. The condition usually also causes uncomfortable sensations in the legs.
RLS may occur during both wakefulness and sleep. People who experience RLS when awake may have difficulty getting to sleep.
If RLS happens during sleep, it may cause a person’s legs to spasm or jerk repeatedly throughout the night. While this may not be enough to wake the person, it can prevent them from reaching the stages of deep, restful sleep. As a result, the person may feel sluggish and tired the following day.
Some scientists believe that RLS is due to abnormalities in the neurotransmitter dopamine, which plays a role in controlling muscle movements.
Certain lifestyle changes may be beneficial for people with milder cases of RLS. These include:
- adopting good sleeping habits
- exercising regularly
- quitting smoking
People with more severe cases of RLS may need medication to regulate the levels of dopamine and iron in the body.
Narcolepsy is a neurological condition that causes a person to fall asleep suddenly and at inappropriate times.
People with narcolepsy usually experience extreme and persistent sleepiness throughout the day. Most people with this condition will also have one or more of the following symptoms:
- sleep disturbances
- sleep paralysis
Treatment usually involves stimulant medications, which help the person stay awake. Antidepressant medications may help control hallucinations and episodes of sleep paralysis.
Doctors may also recommend that people take a few good naps throughout the day, as this can improve narcolepsy symptoms.
Depression may contribute to sleep issues, including excessive daytime sleepiness, as well as oversleeping, or sleep that is not restful. Likewise, sleep issues may contribute to symptoms of depression.
General fatigue and daytime tiredness are common among people with depression. Other symptoms of depression include:
- feelings of sadness
- feelings of hopelessness or despair
- feelings of anxiety
- difficulty concentrating
- difficulty remembering details
Treatment for depression may involve drug therapy, psychotherapy, or a combination of the two.
Several different types of antidepressant medication are available. A person can talk to their doctor about which medication would be most appropriate for them.
Common psychotherapies for depression include cognitive behavioral therapy (CBT) and interpersonal therapy. According to the Anxiety and Depression Association of America, these therapies appear to be particularly effective in treating depression.
In some cases, daytime sleepiness may be a side effect of a particular medication, such as:
It is important to discuss the side effects of any medication with a doctor. If side effects such as sleepiness are too difficult to deal with, the doctor may recommend a change in medication or dosage.
Excessive sleepiness is not a disorder in itself but a symptom of insufficient sleep or an underlying health condition.
People who experience excessive sleepiness may notice the following:
- mental fog
- inability to focus
Excessive sleepiness may also cause:
- difficulty waking up or getting out of bed in the morning
- feeling sluggish and unmotivated throughout the day
- napping frequently throughout the day
- falling asleep at inappropriate times, such as while driving or during meals
- lapses in attention
- loss of appetite
- difficulty remembering events throughout the day
- difficulty concentrating
- poor performance in work or school activities
A person may experience additional symptoms if their excessive sleepiness is the result of an underlying health condition.
Correctly diagnosing the underlying cause of excessive sleepiness is important for establishing the best treatment.
During the diagnostic procedure, a doctor may ask questions about a person’s lifestyle habits and any medications that they are taking. The doctor may also ask questions relating to mental health.
In some cases, a doctor may order the following diagnostic tests:
- A sleep study called a polysomnography: This test records a person’s brain waves, oxygen levels, and body movements during sleep to assess their sleep cycle.
- Electroencephalogram: This noninvasive test records electrical activity in the brain.
The specific treatment for excessive sleepiness will depend entirely on the cause.
Most healthcare professionals will not want to prescribe highly addictive drugs to assist with sleep, and people who receive a prescription for sleep medications should not take them every day.
However, some general lifestyle changes may help people get a better night’s sleep. These include:
- eating a healthful, balanced diet
- limiting caffeine and alcohol intake
- exercising regularly
- creating a relaxing sleep environment
- taking a warm bath before bedtime
- keeping a consistent sleep schedule
Excessive sleepiness is normal after a night of poor or insufficient sleep. However, persistent sleepiness could be a symptom of a sleep disorder or some other underlying health condition.
Anyone who regularly experiences excessive sleepiness should visit their doctor for a diagnosis. Treating the underlying cause can improve sleep quality, and it may reduce the risk of other complications.
Many treatment plans incorporate simple lifestyle changes that can help improve sleep quality.