Somnolence (Drowsiness)

What is somnolence?

Somnolence, also known as drowsiness, is feeling tired and wanting to fall asleep. This symptom may make you nod off when you don’t want to, like when you’re reading the newspaper or when you should be paying attention (like during a lecture or meeting).

It’s usually a symptom you notice before going to bed. But excessive daytime sleepiness may be a symptom of an underlying medical condition or a side effect of a medication. It might also lead to dangerous outcomes if you drive or do certain tasks while drowsy.

A healthcare provider can help you determine what’s preventing you from staying awake during the daytime and offer treatment options so you can feel better.

Somnolence symptoms

If you have somnolence, you may feel like you:

• Didn’t get enough sleep (even if you slept through the night)
• Are yawning a lot
• Have trouble focusing or concentrating
• Aren’t fully present or alert
• Don’t have enough energy to get through the day
• Find it difficult to make decisions, remember or learn new things
• React slower
• Need a lot of caffeine to stay awake (more than six cups of coffee a day)

What are the types of somnolence?

Two common types of somnolence are:

• Postprandial somnolence. This is also known as a “food coma.” You might feel drowsy after eating a large meal.
• Hypersomnia. This is a condition that causes excessive daytime sleepiness despite getting enough sleep at night.

What are the causes of somnolence?

There are several possible causes of somnolence. One of the most common harmless causes is boredom or having a lack of interest in what’s going on around you.

Sometimes, an underlying condition may be the reason for this symptom. Common conditions that cause drowsiness include, but aren’t limited to, the following:

• Anxiety
• Chronic pain
• Depression
• Diabetes
• Head trauma
• Hypercalcemia
• Hyponatremia
• Hypothyroidism
• Sleep disorders (shift work sleep disorder, insomnia, sleep apnea, narcolepsy, idiopathic hypersomnia, Kleine-Levin syndrome)
• Stress

Somnolence may be a side effect of taking certain medications. Some of the most common medications that cause drowsiness include:

• Antidepressants
• Antihistamines
• Antipsychotics
• Antiseizure medications
• Benzodiazepines
• Opioids
• Sleeping pills

Substances that contribute to substance use disorder like alcohol and opioids (narcotics), among others, may also affect your ability to feel awake.

How is somnolence treated?

If you have occasional somnolence, especially before bedtime, it’s natural to fall asleep to treat this symptom. You should feel refreshed when you wake up.

If somnolence persists during the daytime, you should talk to a healthcare provider. They’ll run diagnostic tests to see what’s causing this symptom. They’ll also take a look at what medications you currently take to see if this symptom is a side effect.

Treatment varies from person to person. If a medication side effect is the culprit, your provider will adjust the dosage or type of medication you take. Don’t change how you take medications unless your provider approves it. Your provider will help you manage any underlying conditions if necessary.

What are the possible complications of not treating drowsiness?

Daytime drowsiness usually happens at unwanted times. You might fall asleep while someone is talking to you or during a movie or meeting, or you may not feel awake enough to participate in your favorite activities. It can interfere with your ability to complete your school or work responsibilities or meet social or relationship commitments.

It can also be dangerous. For example, you may fall asleep while driving. If you experience somnolence, you shouldn’t perform tasks that require your full attention, like operating heavy machinery.

To prevent these complications, check with your healthcare provider before starting a new medication to learn more about the side effects. If you feel tired, ask someone else to drive you so you can safely get to where you need to go.

Can somnolence be prevented?

Not all cases can be prevented, especially if an underlying condition causes it. But you can reduce your risk by:

• Improving your sleep hygiene (like by going to bed and waking up at the same time every day and turning off electronics before bed)
• Participating in a light physical activity or eating a snack to take a break from activities that cause boredom
• Getting adequate sleep for your body’s needs
• Reducing stress
• Eating well-balanced meals
• Choosing non-drowsy, over-the-counter antihistamines to treat allergies or cold and flu symptoms
• Avoiding nicotine close to bedtime

When should drowsiness be treated by a healthcare provider?

Talk to a healthcare provider if:

• You aren’t able to get through your daily routine because of this symptom
• This symptom lasts for days to weeks without improvement
• You experience other symptoms with drowsiness, like mood changes or sleep disturbances