Sleepiness - during the day; Hypersomnia; Somnolence
Drowsiness refers to feeling more sleepy than normal during the day. People who are drowsy may fall asleep in when they do not want to or at times which can lead to safety concerns.
Excessive daytime sleepiness (without a known cause) may be a sign of a sleep disorder.
Depression, anxiety, stress, and boredom can all contribute to excessive sleepiness. However, these conditions more often cause fatigue and apathy.
Drowsiness may be due to the following:
- Long-term (chronic) pain
- Having to work long hours or different shifts (nights, weekends)
- Long-term insomnia and other problems falling or staying asleep
- Changes in blood sodium levels (hyponatremia or hypernatremia)
- Medicines (tranquilizers, sleeping pills, antihistamines, certain painkillers, some psychiatric drugs)
- Not sleeping long enough
- Sleep disorders (such as sleep apnea and narcolepsy)
- Too much calcium in your blood (hypercalcemia)
- Underactive thyroid (hypothyroidism)
You tuck yourself under the covers, turn out the light, and look forward to eight hours of blissful slumber. But, after turning for hours you're still exhausted, and no closer to sleep than when you first got into bed. Let's talk toady about sleep disorders. Sleep disorders fall into four basic categories. The scenario I described, in which you toss and turn because you can't fall asleep, is called insomnia. Another type of insomnia is when you wake up in the middle of the night and can't get back to sleep. Sometimes people get insomnia for a night or two because they're stressed out over a big meeting at work, or they're excited about an upcoming trip. Others can't sleep night after night, and that's called chronic insomnia. People with the second category of sleep disorders have a hard time staying awake during the day, even if they slept well the night before. This is called hypersomnia. Sometimes doctors can't find a cause for hypersomnia. But in many cases, a health condition like fibromyalgia, a thyroid problem, a disease like mononucleosis, obesity, or obstructive sleep apnea, can make you sleepy. If you notice a co-worker is nodding off in the middle of meetings, he might have narcolepsy, a sleep disorder that causes people to sleep uncontrollably at inappropriate times during the day. Narcolepsy isn't only embarrassing, it can be dangerous if you nod off behind the wheel of a car. A sleep rhythm problem means that you can't stick to a normal sleep schedule. Maybe you work the night shift at your job, or you're always traveling to different time zones and are constantly battling jet lag. Well, whatever the cause, the lack of a normal sleep pattern is called a sleep rhythm disorder. And finally, there are the types of sleep disorders that wake you up with a jolt in the middle of the night, and, these are called parasomnias, and they can severely interrupt your sleep. You may walk in your sleep, or act out your dreams. Children often have night terrors, in which they wake up from a deep sleep in a terrified state. The good news is that you don't have to live on fewer hours of sleep, because there are decent treatments for sleep disorders. If you're struggling to sleep throughout the night, and dragging through the day as a result, talk to your doctor, who can refer you to a sleep specialist for an evaluation.
You can relieve drowsiness by treating the cause of the problem. First, determine whether your drowsiness is due to depression, anxiety, boredom, or stress. If you are not sure, talk with your health care provider.
For drowsiness due to medicines, talk to your provider about switching or stopping your medicines. But, DO NOT stop taking or change your medicine without first talking to your provider.
Do not drive when drowsy.
What to Expect at Your Office Visit
Your provider will examine you to determine the cause of your drowsiness. You will be asked about your sleep patterns and health. Questions may include:
- How well do you sleep?
- How much do you sleep?
- Do you snore?
- Do you fall asleep during the day when you do not plan to nap (such as when watching TV or reading)? If so, do you awake feeling refreshed? How often does this happen?
- Are you depressed, anxious, stressed, or bored?
- What medicines do you take?
- What have you done to try to relieve the drowsiness? How well did it work?
- What other symptoms do you have?
Tests that may be done include:
- Blood tests (such as a CBC and blood differential, blood sugar level, electrolytes, and thyroid hormone levels)
- CT or MRI scan of the head
- Electroencephalogram (EEG)
- Sleep studies
- Urine tests (such as a urinalysis)
Treatment depends on the cause of your drowsiness.
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Hirshkowitz M, Sharafkhaneh A. Evaluating sleepiness. In: Kryger M, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. 6th ed. Philadelphia, PA: Elsevier; 2017:chap 169.
Mansukhani MP, Kolla BP, St.Louis EK, Morgenthaler TI. Sleep disorders. In: Kellerman RD, Rakel DP, eds. Conn's Current Therapy 2021. Philadelphia, PA: Elsevier 2021:755-770.
Last reviewed on: 7/14/2021
Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.