There are three disadvantages of lack of sleep which are causing diseases, an effect to the skin health and weight gain. Firstly, the lack of sleep can diseases. The living of modernists has activities at night, which consist of the party with friends and they are reading books for an exam that causes. For example, when you lack sleep for a long time, it accumulates of proteins at the heart, and lead to the risk of heart disease. Secondly, the lack of sleep leads to effect the health of the skin. For example dull skin, fine lines on the face and dark circles under the eyes are happened by the chronic lack of sleep. Lastly, the lack of sleep can cause weight gain. The cause of weight gain is the abnormal metabolic process blood sugar to make lacking blood sugar, so it makes more food. For example, when some people watch TV late at night, they were eating the snack which causes weight gain. In conclusion, diseases, an effect to the health of skin and weight gain are three significant disadvantages of lack of sleep.