If you take a bath or work with water for a long time, you must have noticed that the skin of the fingertips has wrinkled. Almost everyone knows this. But do you know the root cause of this skin wrinkle ? Then know , in fact, but the skin does not wrinkle. Rather, another event happened! And we think the skin is wrinkled. The skin of our body is made up of several layers. The last layer of our skin is called the epidermis. From this epidermis comes a kind of oily substance called sebum. This sebum acts as a protective screen for our skin. When we touch glass or any other smooth surface, our handprints are there , even if our hands are clean. This oily impression is sebam. This work is done because of the service. This sebum prevents water from entering the inner layer of our skin when we are in contact with water for some time. But if we hold water for a long time, this sebum of our hands goes away and water enters inside the skin. That is, our skin absorbs water and the inner layer of the epidermis enters the dermis. Then the places where there is no bond between dermis and epidermis swell by absorbing water and the places where there is bond between dermis and epidermis remain the same. So to us the skin seems to have wrinkled.