Daytime Fatigue: The Cost of Insomnia

Medically Reviewed by Carmelita Swiner, MD on September 02, 2022
3 min read

Most people know the dangers of drinking and driving, but think nothing of getting behind the wheel after a sleepless night. But the daytime effect of little or no sleep can hinder your driving skills to the point where you're impaired as if you've had too much to drink.

People with insomnia are more likely than well-rested people to have a car crash due to fatigue. Lack of sleep is also the cause of over 7% of all serious accidents in the workplace.

In addition, people with insomnia are more likely to:

  • Miss work
  • Make bad decisions
  • Take more risks
  • Have trouble concentrating
  • Be irritable
  • Be depressed
  • Eat foods high in calories

According to experts, chronic insomnia affects one in 10 people. And while insomnia can affect your safety and the quality of life during the hours you're awake, it can also increase your risk for a variety of other health problems. In addition to causing daytime fatigue, insomnia increases your risk for other health problems, including:

  • Heart disease
  • Stroke
  • High blood pressure
  • Infections
  • Obesity
  • Diabetes
  • Depression
  • Pain
  • Substance abuse
  • Early death

Sleep affects our ability to think, react, remember, and solve problems. The catch is that we may develop some tolerance to lack of sleep and aren’t aware how much our alertness and performance is really suffering.

It’s important to distinguish insomnia-related daytime fatigue from excessive daytime sleepiness (EDS). The terms are often used interchangeably, even among medical researchers. There are distinct differences, however.

People with EDS feel so drowsy during the day that they’ll typically fall asleep during the day if they’re in a boring or sedentary situation. They might fall asleep while stopped at a stoplight or sitting in a waiting room. EDS is usually caused by conditions like sleep apnea, restless leg syndrome, narcolepsy, neurologic conditions such as Parkinson's disease, as well as many medications.

People with daytime fatigue are very tired but usually don’t fall asleep during the day. They struggle to get through a normal day’s activities. Symptoms of daytime fatigue include:

  • Weariness, weakness, and/or depleted energy
  • Lack of motivation
  • Poor performance
  • Memory problems
  • Lack of productivity
  • Tendency to make errors and mistakes
  • Depression
  • Low interest in being social

Fatigue is a more accurate description of what people with insomnia experience. Although they’re sleep deprived, they tend to feel more tired than sleepy. If you have insomnia, you might find it hard to nap. People with insomnia usually see a doctor because of fatigue and poor daytime functioning, not because they have trouble falling or staying asleep.

Your first step to getting rid of daytime fatigue is to figure out what’s causing it. In addition to insomnia, many other issues can  cause fatigue. These include other sleep disorders, diabetes, arthritis, asthma, and chronic fatigue syndrome. It could also include interrupted sleep patterns from breastfeeding, chronic pain or frequent urination from an enlarged prostate or uncontrolled diabetes.

Fatigue is also a side effect of certain medications. Make an appointment with your doctor so that they can assess your symptoms. If you have trouble going to sleep or staying asleep, tell the doctor. There are effective treatments for insomnia, including cognitive behavioral therapy and medication. These can greatly improve how you feel and function during the day.