6 reasons why you feel tired all the time and how to treat each one, according to sleep experts

• Sleeping a lot could be due to a condition like narcolepsy, which causes sudden bouts of sleepiness.
• Taking medications like antidepressants, pain meds, allergy meds, and more can also cause tiredness.

It's normal to feel mild daytime sleepiness once in a while, but if you're feeling excessive sleepiness suddenly or often that's causing you to sleep more than the recommended 7-8 hours, this can be a cause for concern.

Not to mention, feeling tired and worn out all the time can get in the way of your day-to-day, and can even be dangerous in the case of operating a car or other machinery.

Here are six reasons for excessive daytime sleepiness and how to treat it and get your life back on track.

1. Sleep debt

Sleep debt is a real condition that occurs when you aren't getting enough sleep over a series of multiple days compared to what you typically get and need. For example, if a person who usually gets eight hours of sleep suddenly has a few days of only getting six hours, they'll go into sleep debt.

This debt builds up over time — the more sleep debt you accrue, the more sleepy you may feel and the longer it takes to return to your baseline.

Though sleep debt can occur simply because life has gotten in the way of getting a good night's rest, it can also be a result of a health issue. Some medical conditions that can prevent you from getting a good night's sleep are:

• Alzheimer's disease
• Cancer
• Depression
• Head injuries
• Intellectual disabilities
• Pregnancy
• Schizophrenia
• Stroke

Sleep debt can result from even one single night of insufficient sleep, and it can take several days to recover, says Alex Dimitriu, MD, board-certified psychiatrist and sleep medicine specialist and founder of Menlo Park Psychiatry and Sleep Medicine.

Aside from excessive sleepiness, you may notice cognitive impairments such as:

• Trouble with memory
• Slower thinking
• Shorter attention span
• Irritability

Treatment: In order to recover from sleep debt, you need to get adequate sleep. Dimitriu says you should make sure you're getting at least seven or eight hours of sleep per night, and ideally going to sleep and waking up at around the same times each night and morning.

According to the CDC, you sleep more deeply when you are sleep deprived, so you don't need to "pay back" every single hour of lost sleep. But, the agency says, it may take several nights to feel better again.

You should also avoid flip-flop sleep patterns where you continuously undersleep one night and oversleep the next night, says Dimitriu. Instead, aim for a consistent amount of sleep every night.

2. Drinking caffeine or alcohol

"Sleep quality is as important as sleep quantity. It's important for the brain to go through the proper sleep stages at night, and many substances can disturb this," says Dimitriu.

For example, he says that two common offenders are caffeine and alcohol:

• Caffeine can cause you to take longer to fall asleep, have lower quality sleep, and have shorter overall sleep time. A 2013 study found that having caffeine six hours before bed reduced total sleep time by over an hour.
• Alcohol can lead to lower quality sleep because it reduces the amount of REM sleep you get and can contribute to insomnia. A 2018 study found moderate alcohol intake reduced sleep quality by 24%, and high alcohol intake resulted in a 39.2% reduction.

Note: The CDC defines moderate drinking as two or fewer drinks per day for men and one or fewer drinks per day for women. Heavy drinking is considered eight or more drinks per week for a woman or 15 or more drinks per week for a man.

Treatment: Reducing your alcohol and/or caffeine intake, particularly closer to bedtime, can help improve your overall sleep quality, resulting in less daytime sleepiness.

Ideally, you should stop drinking caffeine six hours before bed and alcohol four hours before bed. You may even want to experiment with sobriety to see if that helps you get a good night's sleep.

3. Medications

Various medications can cause excessive sleepiness, says Dimitriu. You may especially notice these side effects when you first start taking a medication.

Examples of medications that cause sleepiness are:

• Allergy medications
• Anti-anxiety medications
• Antidepressants
• Antipsychotics
• Anticonvulsants
• High blood pressure medication
• Muscle relaxants
• Pain meds

Treatment: Speak to your doctor if you think your prescriptions are making you extra sleepy.

It's possible that your body just needs to adjust to the medication, or, you may be able to take it at a different time of day that works better for you. For some medications that may have sleepiness as a side effect, it's best to take them right before bed, instead of in the morning.

But do not stop taking medication as prescribed before talking to a medical professional.

4. Sleep apnea

Sleep apnea is an extremely common condition, affecting about 25% of men and 10% of women. It causes you to temporarily stop breathing throughout the night, resulting in sleep disturbances and lower sleep quality, says Meir Kryger, MD, board-certified pulmonologist and sleep medicine specialist at Yale Medicine.

If you share a bed with someone, they may report that they hear you snore loudly or that they've witnessed you stop breathing in the night, which can be telltale signs of sleep apnea, says Kryger.

Other symptoms of sleep apnea include:

• Trouble staying asleep
• Waking up with dry mouth
• Headaches in the morning
• Irritability
• Trouble concentrating

You may be most at risk for sleep apnea if you are over 50 or overweight.

Treatment: If sleep tests determine that you have sleep apnea, treatment will depend on the severity of your condition.

Mild cases may respond to lifestyle changes, such as losing weight if you're overweight. However, in moderate or severe cases, the most common treatment is using a continuous positive airway pressure (CPAP) machine to help keep your airways open.

If a CPAP machine isn't right for you, oral appliances, like tongue-stabilizing devices, may be another option.

5. Narcolepsy

If you are extremely tired during the day — even to the point of falling asleep suddenly wherever you are, you might be experiencing narcolepsy, says Kryger.

The condition is relatively uncommon, affecting only around one in every 2,000 people in the US and Western Europe.

Narcolepsy is a condition where the brain has trouble controlling your sleep-wake cycles. Kryger says you may also experience symptoms such as:

• Hallucinations, particularly upon falling asleep or waking up.
• Cataplexy, which is a sudden loss of muscle tone that can result in weakness or even collapsing, typically upon feeling a strong emotion like anger or excitement.
• Sleep paralysis, when you temporarily can't move or speak, usually around the time of falling asleep or waking up.

Treatment: Narcolepsy is typically lifelong but medications can help prevent severe symptoms and help manage the condition. Treatment options include prescription medications such as:

• Stimulants
• Antidepressants
• Sodium oxybate (a potent sedative taken at night)

6. Restless leg syndrome

Restless leg syndrome's main symptom is extreme discomfort in the legs resulting in an irresistible urge to move them, says Kryger.

The sensation can range from achiness to feeling like your skin is crawling, and giving into the urge to move your legs can temporarily relieve the discomfort.

This phenomenon usually worsens when you're resting and/or at nighttime, which can lead to trouble falling asleep and getting back to sleep upon waking up in the middle of the night. Since your sleep is disrupted, you may find yourself excessively tired the next day.

Additionally, you may experience frequent leg twitches while you sleep. The decrease in amount of sleep and sleep quality can lead to daytime sleepiness.

Treatment: In many cases, there isn't a known cause for someone's restless leg syndrome, but sometimes it can be due to an iron deficiency, Kryger says. In this case, iron supplementation may help treat the syndrome. In other scenarios, treatment includes various medications such as:

• Anti-seizure medications
• Medications that raise dopamine levels (such as Neupro and Mirapex)
• Muscle relaxants
• Opioids

Insider's takeaway

If excessive daytime sleepiness is interfering with your day-to-day life, check in with your doctor or a sleep specialist to determine the cause.

Whether you simply need to get more sleep every night or take medication to manage a condition, a medical professional can get you on track to feeling more well-rested and alert.