1. You Always Feel Hungry
Lack of sleep influences hormone levels, including increasing the
"hunger hormone" ghrelin and decreasing leptin, which is involved in
satiety. By activating your endocannabinoid system, which is involved in
modulating appetite and food intake, sleep deprivation can even give
you the
munchies, similar to marijuana use.
2. You've Gained Weight
One of the consequences of eating more when you're sleep deprived is
weight gain, although lack of sleep also promotes metabolic dysfunction
that further fuels weight gain. Losing as little as 30 minutes of sleep
each night can disrupt your metabolism enough to cause weight gain. In
fact, each half-hour of sleep debt incurred during weeknights raised one
study's participants' risk for obesity and insulin resistance by 17
percent and 39 percent respectively after one year.
4
What this means is that if you need eight hours of sleep but
consistently only get seven, you may theoretically raise your risk of
obesity by about 34 percent and simultaneously jack up your chances of
insulin resistance — which is a hallmark of most chronic diseases, including
type 2 diabetes — by 78 percent.
3. Your Memory Fails You
The process of brain growth, or neuroplasticity, is believed to
underlie your brain's capacity to control behavior, including learning
and memory. However, sleep and sleep loss modify the expression of
several genes and gene products that may be important for synaptic
plasticity.
Furthermore, certain forms of long-term potentiation, a neural process associated with the laying down of
learning and memory can be elicited in sleep, suggesting synaptic connections are strengthened while you slumber.
4. It's Difficult to Make Decisions
Sleep deprivation leads to accidents both big and small, some of
which prove to be fatal, in part because it leads to blunted reaction
times and difficulty making decisions. Participants in one study
underwent two nights of total sleep deprivation followed by two nights
of recovery sleep, then performed a decision-making test.
5
A well-rested control group (who had slept normally) performed better
on the tests than the sleep-deprived group, but, worse yet, when the
test rules were reversed none of the sleep-deprived volunteers got the
right answer, even after 40 tries, leading the study's lead author to
state their ability to take in new information was "completely
devastated."
6
5. Your Reaction Time Slows
In the aforementioned study, the researchers concluded that sleep
deprivation is particularly problematic for decision-making involving
uncertainty and unexpected change. This leads to blunted reaction times
that can have tragic consequences while you're driving or on the job.
6. You're Overly Emotional
Lack of sleep kicks your emotions into high gear, which means you're
likely to overreact when expressing emotions like fear and anger. Your
brain's frontal cortex, for instance, plays a key role in the regulation
of emotions, and sleep is vital for its function. Not to mention that
research shows even one night of too little sleep may lead to unwanted
behavior at work the next day, such as acting rude toward co-workers,
theft or going home early without notifying the boss.
7
7. You're Always Getting Sick
Sleep deprivation has the same effect on your immune system as physical stress or illness,
8
which may help explain why lack of sleep is tied to an increased risk
of numerous chronic diseases and acute illnesses like colds and flu. In
fact, research shows adults who sleep less than six hours a night have a
four times higher risk of catching a cold when directly exposed to the
virus than those who get at least seven hours.
9
Sleeping less than five hours per night resulted in a 4.5 times
higher risk. The study found that sleep was more important than any
other factor when it came to protecting against the cold virus,
including stress levels, age and smoking. In short, if you want your
immune system to be at its best, adequate sleep is essential. The
researchers, writing in the journal Sleep, explained:
10
"Growing evidence demonstrates that short sleep duration (< 6
or 7 h/night) and poor sleep continuity are associated with the onset
and development of a number of chronic illnesses, susceptibility to
acute infectious illness, and premature mortality. Experimental evidence
in animals and humans suggests that the immune system serves as a key
biological pathway.
For instance, total and partial sleep deprivation in humans
results in modulation of immune parameters critical to host resistance,
including diminished T cell proliferation, shifts in T helper cell
cytokine responses, decreases in natural killer (NK) cell cytotoxicity,
and increased activation of proinflammatory pathways."
8. Your Vision Seems Unfocused
Even your vision is affected by lack of sleep. According to Health,
when you're tired your ciliary muscle, which helps your eyes focus, will
not work up to par and "the extraocular muscles, which move the eye
from side to side and up and down, may start to track improperly,
resulting in double vision."
11 So, if you seem to be having trouble seeing after a night of little sleep, it's probably not in your imagination.
9. Your Physical Appearance Suffers
Lack of sleep affects your physical appearance significantly, in part
because it alters your hormonal balance, which can lead to
acne, and decreases collagen production, which may increase the appearance of wrinkles.
Further, one study took photos of 23 people with the same hairstyles,
facial expressions and bare (no makeup) skin. The only difference
between them was the amount of sleep they'd had—one group had a full
night's sleep while the other group had been awake for 31 hours straight
and then slept for just five hours.
Not surprisingly, when the photos were shown to a separate group of
people, they rated the sleep-deprived group as less healthy, less
attractive and more tired, suggesting that the idea of "beauty sleep" is
not just a fairy tale.
12
10. You Nod Off During the Day
You might be able to fool your body into believing you can function
normally on little sleep, but as reported in the journal Sleep, as soon
as you let your guard down, overwhelming sleepiness ensues.
13
Your body will likely cave in to these episodes of "microsleeps" or
nodding off, which can be tragic depending on your line of work or if
you fall asleep while behind the wheel.
In a report released by the AAA Foundation for Traffic Safety,
researchers compared driving drowsy to driving with a blood alcohol
concentration considered legally drunk.
14
Lack of sleep, even by one or two hours, nearly doubled study
participants' risk of a car accident the following day. If sleep
deprivation increased, with participants sleeping just four or five
hours a night, their risk of a car
crash quadrupled.
15 According to the AAA Foundation for Traffic Safety:
16
References:
