Lack of sleep is one of the major contributors of fatigue, loss of resistance, poor concentration and bad mood. But these are just the the immediate effects of not sleeping enough, for it carries a lot of health risks.

Here are some of the adverse health effects of lack of sleep:

1. It increases the risk of colon cancer.

According to a study published in the journal Cancer, people who sleep less than six hours per night have almost 50 percent chances of developing colorectal adenomas than people who get seven hours of sleep per night on average. Adenomas are a precursor to cancer tumors and they can become malignant if left untreated.

2. It increases the risk of diabetes.

A 10-year study conducted by Harvard University researchers reported that one in three of the women who sleep less than five hours a night is more likely to develop diabetes. The connection between sleep and diabetes is not clear but researchers believe that lack of sleep may reduce levels of leptin, a hormone that sends signals to the brain that the stomach is full. Low levels of leptin can be a cause for overeating, and this can lead to obesity and diabetes if this goes on for a long time.

3. It increases the risk for heart diseases.

A study conducted by the University of Chicago found that insufficient sleep can trigger the increase of the stress hormone cortisol in the afternoon and evening. This in turn can also cause an increase in heart rate, blood pressure and blood glucose. An increase in cortisol during bedtime is not healthy as it can keep you awake and alert when you should be sleeping.

The study asserted further that sleep deprivation may raise the risk of heart diseases because it can cause high blood pressure, pump extra stress hormones into the bloodstream and raise your blood sugar level.

4. It can cause depression and irritability.

It is not strange to see people having mood swings and getting depressed after going through a series of sleepless nights. Sleep has a direct connection to people’s mood and demeanor.

A 2002 poll conducted by the National sleep Foundation on people with sleep problems says that among the participants of their survey, 21 percent claimed that they were not satisfied with life, and 12 percent asserted that they were angry. Almost 50 percent of them have problems getting along with their friends and relatives and more than 60 percent said that they don’t have patience to wait in lines or to get stuck in traffic.

These findings are in contrast to the claims given by survey participants who had sufficient sleep. They describe themselves as being “relaxed” and “full of energy.”