Drowsiness refers to feeling abnormally sleepy during the day. People who are drowsy may fall asleep in inappropriate situations or at inappropriate times.

Sleepiness - during the day; Hypersomnia; Somnolence

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. But these conditions more often cause fatigue and apathy.

Drowsiness may be due to the following:

• Chronic pain
• Diabetes
• Having to work long hours or different shifts (nights, weekends)
• Changes in blood sodium levels (hyponatremia /hypernatremia)
• Medicines (tranquilizers, sleeping pills, antihistamines)
• Not sleeping for long enough
• Sleep disorders (such as sleep apnea syndrome and narcolepsy)
• Too much calcium in your blood (hypercalcemia)
• Underactive thyroid (hypothyroidism)

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 health care provider about switching or stopping your medicines. Never stop taking or change your medicine without first talking to your health care provider.

The doctor will examine you to determine the cause of your drowsiness and ask 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 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 scan of the head
• Electroencephalogram EEG
• Sleep studies
• Urine tests (such as a urinalysis)

Treatment depends on the cause of your drowsiness.

Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa.: Elsevier Saunders; 2011:chap 403.

Mahowald MW. Disorders of sleep. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa.: Elsevier Saunders; 2011:chap 412.

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