Sleeping Too Little
Credit: Kevin Trageser / Getty Images

Science has pretty much nailed down that people need about 7 to 8 hours of sleep a night. Not getting enough Z's can make you more prone to catching cold and developing obesity and cardiovascular diseases. Proper sleep habits are important for optimal functioning of many of our organs. Since our biggest organ is our skin, sleep also affects our appearance. Lack of it can bring about dark circles, paler skin, and drooping in the corners of the mouth.