While you sleep, your immune system produces protective, infection-fighting antibodies. It uses these antibodies to combat foreign invaders such as bacteria, cold and the flu. With our immune systems hard at work defending our bodies all the time, most of us will not often fall ill. For people that suffer from sleep deprivation, however, our immune system is not able to work properly and falling ill may become a more regular occurrence.

As you wake up throughout the night, this can cause sleep deprivation, which leaves you more vulnerable to infections. Sleep deprivation prevents your immune system from building up its forces and can directly affect the immune system. This means that we are more likely to fall ill to common illnesses such as the cold and flu more often.

It also increases our chances of contracting more serious illnesses and reduces our ability to fight illnesses once we have caught them. If you don’t get enough sleep, and it may also take you longer to recover.

6. You're Always Hungry

Running low on sleep can increase the production levels of two hormones Ghrelin and Leptin which control feelings of hunger and fullness also known as the hunger hormones. Leptin tells your brain that you’ve had enough to eat. Without enough sleep, your brain reduces Leptin and raises Ghrelin, which is an appetite stimulant.

Too much Ghrelin makes your body crave fatty and sugary foods, so when you're not sleeping properly you tend to eat more of what you're craving because you're not feeling the signals to stop eating. The flux of these hormones could explain night time snacking or why someone may overeat later in the night.

With increased appetite comes another unpleasant symptom of sleep deprivation which is weight gain. Lack of sleep can affect numerous hormones which can stimulate your appetite and slow down metabolism. When you're tired, you often don't watch what you eat and look for all kinds of things to help you feel more awake. Eating more means more calories which can cause us to become fat.  

It will also become especially difficult to exercise if you are feeling too tired to do so. A lack of sleep can also make you feel too tired to exercise and over time, reduced physical activity can make you gain weight because you’re not burning enough calories and not building muscle mass. Excess weight can lead to significant health problems, so it is important to exercise and eat well when possible.

Healthy living also helps to improve your quality of life overall, so everyone should do what they can to keep in shape. If you are having difficulty sleeping, though, keeping the extra weight off can be a lot harder.

8. High Blood Pressure

Sleep affects processes that keep your heart and blood vessels healthy. The constant flow of blood around our bodies is essential for us to live. In order to achieve a constant flow, the blood needs to be pumped at a certain pressure to ensure it circulates throughout the entire body. Without it our bodies would be starved of the nutrients that are carried in the bloodstream.

Despite the need for a certain blood pressure, however, things can get dangerous if your blood pressure becomes too high. A lack of sleep can lead to a high blood pressure and this could cause some potentially serious complications, like a stroke. If you have high blood pressure you should arrange to speak with a doctor as soon as possible.

Sleep is essential in our lives and depending on the level of sleep deprivation, many functions in our body are going to be affected. One of the biggest issues associated with lack of quality sleep is with memory.

Studies show that that lack of sleep damages memory, and people who don’t get enough sleep can have difficulty remembering things. While we are sleeping, events occur in the brain that help memories to become firmly implanted in our minds. Sleep is important because it allows our brain to assimilate new information that we have learned into solid memories.  Since the brain does not have sufficient time to create new pathways for the information you’ve recently learned, sleep deprivation often affects how memories are consolidated.  

10. Paranoia and Hallucinations

Did you know that being exhausted all the time doesn't just dent your health and your productivity? It can also make you paranoid. People who experience prolonged periods of limited bedtime can become disoriented. They may not register the passage of time, or even know what day it is. This can be accompanied by visual hallucinations and paranoid thinking that someone is out to get them.

This effect is much more common in people who have been awake for days on end and won’t likely be a problem for people who are simply missing an hour or two of sleep every night. People with very severe insomnia may begin to feel afraid of things that they weren’t normally afraid of. The longer you go without sleeping, the more likely you are to experience paranoia.

Seeing things that aren't there can be a side effect of chronic sleep deprivation.  People who have not slept in 48 hours or more may begin to experience hallucinations. People often say they feel loopy after a night of no sleep. However, if a person goes days or weeks without sleeping, these hallucinations can become more and more vivid. They may see people that are not there or find themselves engaging in situations that are only apparent to them. Again, not everyone who experiences sleep deprivation will have these symptoms, but they’re certainly something to watch out for.

Beauty Sleep is a common term that implies that sleep helps us to look better. For the most part, it is quite accurate as lack of sleep can have quite an effect on a person’s appearance. Anyone who cares about their complexion should know that lack of sleep affects skin quality. The body utilizes sleeping time to produce hormones that repair damaged tissues. If you cut down too much on the amount of time you sleep, you deprive the body of these self-repair opportunities.

Most of us inherently know that lack of sleep the night before can lead to a day of feeling exhausted, unfocused and even grumpy or emotional. The best way to prevent sleep deprivation is to make sure you get adequate sleep. Follow the recommended guidelines for your age group, which is 7 to 9 hours for most adults.

Other ways you can get back on track with a healthy sleep schedule include:

If you continue to have problems sleeping at night and are fighting daytime fatigue, talk to your doctor. They can test for underlying health conditions that might be getting in the way of your sleep schedule.