Sleep and How it Affects Our Health

Studies have revealed that lack of sleep is linked to an increased risk of chronic disease. Getting enough sleep every night is an important factor in preventing diseases.

At one time or another, each of us has stayed up past our bedtime resulting in lack of sleep – and suffered for it the next day. You are familiar with the effects of sleep deprivation such as exhaustion, irritability, or inability to concentrate on our tasks. We all know we need to get more sleep but most of us don’t get it, pushing it back in favor of studying, working or partying. However, many people are unaware that regularly losing out on sleep has been linked to an increased risk of various chronic diseases including diabetes, hypertension, and heart disease. Getting enough sleep is more significant to disease prevention than we think, and we all need to be getting more of it if we want to improve our quality of life.

On the other hand, getting too much sleep also carries some risks with it, such as diabetes, obesity, headaches, back pain, depression, and heart disease.

Sleep Duration Recommendations

In February 2015, the National Sleep Foundation (NSF), together with a mutli-disciplinary panel, issued new recommendations for appropriate age-specific sleep durations.

Age Recommended May be appropriate Not recommended
(0-3 months)
14 to 17 hours 11 to 13 hours
18 to 19 hours
Less than 11 hours
More than 19 hours
(4-11 months)
12 to 15 hours 10 to 11 hours
16 to 18 hours
Less than 10 hours
More than 18 hours
(1-2 years)
11 to 14 hours 9 to 10 hours
15 to 16 hours
Less than hours
More than 16 hours
(3-5 years)
10 to 13 hours 8 to 9 hours
12 hours
Less than 7 hours
More than 12 hours
School-aged children
(6-13 years)
9 to 11 hours 7 to 8 hours
12 hours
Less than 7 hours
More than 12 hours
(14-17 years)
8 to 10 hours 7 hours
11 hours
Less than 7 hours
More than 11 hours
Young Adults
(18-25 years)
7 to 9 hours 6 hours
10 to 11 hours
Less than 6 hours
More than 11 hours
(26-65 years)
7 to 9 hours 6 hours
10 hours
Less than 6 hours
More than 10 hours
Older Adults
(≥65 years)
7 to 8 hours 5 to 6 hours
9 hours
Less than 5 hours
More than 9 hours

Source: National Sleep Foundation (

Diseases Linked with Lack of Sleep

Insufficient sleep can lead to the following medical conditions:

  • Obesity – there are several studies that have revealed a link between lack of sleep and weight gain, as poor sleep leads to an increase in the production of cortisol or the ‘stress hormone’, as well as an increase in the secretion of insulin.
  • Diabetes – lack of sleep can lead to type 2 diabetes.
  • Heart disease and hypertension – insufficient sleep can cause elevated blood pressure the next day.
  • Mood disorders – regular sleep deprivation can lead to long-term mood disorders, such as depression, anxiety, and mental distress.

Other Consequences of Sleep Deprivation

Aside from the serious medical consequences of not getting enough sleep, those who are regularly sleep deprived experience reduced efficiency and productivity and become more error- and accident-prone.

According to the National Highway Traffic Safety Administration:

  • There were 846 fatalities in 2014, (2.6% of all fatalities) that were related to drowsy-driving.
  • There was an estimated average of 83,000 crashes each year between 2005 and 2009 related to drowsy-driving, including almost 886 fatal crashes (2.5% of all fatal crashes), an estimated 37,000 injury crashes, and an estimated 45,000 property damage only crashes.
  • Over the last decade, more than 7,000 people have died in drowsy-driving-related crashes.

In addition, the following disasters can be attributed to people whose job performance suffered due to sleep deprivation:

  • Chernobyl Explosion – The worst nuclear disaster in history was ruled by investigators as caused by engineers who had worked for 13 hours or more. The actual number of deaths resulting in the explosion is undetermined; however, 240 cases of radiation sickness were reported initially, followed by dozens of deaths in the following weeks.
  • Three Mile Island – Human error due to sleep deprivation was to blame for the accident, according to the official investigation. The cleanup efforts cost $1 billion, and as a result of the incident, plans for reactors in the U.S. were abandoned.
  • Exxon Valdez Spill – Due to layoffs among the ship’s crew, those who remained ended up working 12 to 14 hour shifts, and this caused the third mate to fall asleep on the wheel around 1 a.m. The ship ran aground in Alaska, destroying wildlife and spilling 258,000 barrels of crude oil.
  • The Challenger Explosion – Within seconds of launching in January 1986, the Challenger space shuttle exploded, killing all seven crew members. The accident was attributed to the fact that managers involved in the launch had only been able to get 2 hours of sleep before reporting for work at 1 a.m. that fateful -morning.
  • American Airlines Flight 1420 Crash – On June 1, 1999, 11 people died and 105 people sustained injuries when American Airlines Flight 1420 missed the runway at Little Rock. While severe thunderstorms played a role in the crash, the National Transportation Safety Board ruled that the crash was a result of ‘impaired performance resulting in fatigue.”