Sleep Deprivation Effects and Symptoms

Sleep deprivation is a relatively common problem yet many people are not familiar with it. Most of us think of interrogation techniques and other serious medical problems where a person has not slept for days when we hear the term sleep deprivation. But missing even one night’s sleep can have a host of effects on the body. In fact these effects due to a lack of sleep has been cited among the most common causes of road traffic accidents across the globe. But it is impacting on many people everyday, even off the road, and contributes to work, family and health problems.

How much sleep is enough?

You may feel that you can manage well on just 4 to 5 hours of sleep but this is actually too little sleep for your body. The average adult requires about 7 to 9 hours and young children may need to sleep even longer. You could probably cope well on as little as 6 hours of sleep but it is not sufficient in the long run. The daily quantity of sleep is so significant that long term insomnia has been linked to an increased risk of depression, strokes, hypertension and other medical ailments.

Some people find that short naps during the day helps to make up for lost sleep. If this is a luxury that you can afford then by all means you should take the opportunity. However, it cannot fully replace a good night’ sleep of at least 7 hours, if not more. Power naps, which are usually 20 to 30 minutes, are helpful in giving you a short term boost but cannot make up either for the lack of sleep at night. There is almost no part of the body that is unaffected by a lack of sleep but we will focus on the most pronounced effects below.



The effects of sleep deprivation on mental abilities is probably the most obvious. Sleep deprivation is associated with:

  • Poor memory
  • Difficulty with decision-making
  • Trouble concentrating
  • Mood swings
  • Inability to handle stress as normal

These symptoms are further compounded with fatigue and by the end of a day, a person’s mental capability may be so impaired that it can lead to irrational and rash decisions and affect normal daily functioning. It is not surprising then that it has been found that insomnia can affect interpersonal relationships.



Although all the senses can be affected with sleep deprivation, the eyes and vision are probably the most severely compromised. Bloodshot eyes are often evident, as well as with darkening around the eyes, puffy bags below it and sometimes even squinting more than normal due to light sensitivity.

Vision problems include a range of symptoms such as fuzziness of objects, reduced peripheral vision and a difficulty with quickly focusing on objects of varying distances. These visual distortions are dangerous as it can lead to mishaps from simple falls within the homes, to injuries if operating heavy equipment and even motor vehicle accidents.


The muscles in the body are affected in a number of ways. Poor coordination and muscle weakness are common symptoms. Some people may experience slight tremors. Even simple physical tasks that are done daily may be a strain and difficult in completing as normal. Reaction times are also slower which can be particularly dangerous when driving or operating heavy machinery.

Sometimes there may be fumbling with small objects, even with something as simple as inserting a key in a door lock. The effects are not just limited to the arm or hand muscles. You may be just as uncoordinated on your feet. Difficulty standing still or walking in a straight line are other symptoms of sleep deprivation. It can sometime mimic alcohol intoxication.


Sleep deprivation has a host of effects on the cardivascular system but most people are not immediately aware of it as it is not always obvious. The heart rhythm may be disturbed and the blood pressure may increase as peripheral blood vessels may become narrower. It is not an immediate problem for most people but people with pre-existing cardiovascular problems may be at risk of serious events.

Blood flow to areas requiring an increased supply of blood may also be affected. This can lead to dizziness when the brain is not getting enough blood, digestion problems due to impaired flow to the gastrointestinal tract especially after eating and even muscle cramps from insufficient blood flow during physical activity.



Changes in appetite are common with sleep deprivation. While some people may experience a loss of appetite, others may find that their appetites increase. There may also be a craving for sugary foods and drinks as well as caffeinated beverages to boost energy levels for short periods.

Collectively these changes in appetite coupled with less physical activity from fatigue and a host of hormonal changes can contribute to obesity. It is important to note that sleep problems do not cause obesity on its own but affects various processes in the body that increases the likelihood of weight gain.


There are a number of glands and hormones that are affected with sleep deprivation. The body’s response to hormones secreted by different glands may therefore also be affected. As a result a person may feel very fatigued, have a lower body temperature, higher blood glucose levels and a number of other endocrine disturbances as a result of sleep deprivation.

Although these hormonal alterations are serious for all people, it is more so for diabetics. Sleep deprivation reduces the body’s sensitivity to insulin, the hormone that is responsible for lowering blood sugar levels. Another hormone related problem applies to growth hormone. It is important for growth especially in babies, children and adolescents and also contributes to wound healing.

sleeping baby


The immune system is very sensitive to even subtle disturbances in the body. Apart from the influence of hormones and other physiological pathways, it is also known that the immune system may dip with negative mental and emotional states. Collectively this causes weakened immune defenses.

As a result a person is more likely to contract infectious diseases and possibly suffer with it for longer periods than a person with a healthier immune system. The effects on the immune system may also contribute to disturbances in the way the body differentiates its own tissues from foreign particles or harmless substances. This in turn may possibly play a role in the severity of allergies and autoimmune diseases.

Please note that any information or feedback on this website is not intended to replace a consultation with a health care professional and will not constitute a medical diagnosis. By using this website and the comment service you agree to abide by the comment terms and conditions as outlined on this page