What Everyone Should Know About the Effects of Water on Hair

 Have you ever noticed that wet hair is heavier than dry hair? Why is that? The outer layer of your hair, the cuticle, is made up of tightly over lapping scales for strength and resistance. And then there is the sebum, or the natural oil, that coats the scaly cuticle. Despite these 2 defenses, your hair still absorbs water. In fact healthy hair can absorb more than 30% of its own weight of water. Damaged hair is even more permeable - it can absorb up to 45% of its own weight of water. When the hair shaft is fully saturated, its diameter increases by 15 - 20% and it stretches or gets longer. Effects of Water What effect does water then have on hair? When the hair shaft is saturated, the cuticle's structure of the tightly over lapping scales is altered significantly. This causes the hair shaft to be fragile and more easily damaged. Add sunshine to this mix and you have very vulnerable hair. With the scales of the cuticle not offering enough protection, the sunshine can more easily damage the melanain - the part of your hair that is reponsible for color. Therefore, swimming on a hot summer day is refreshing for you, but it is very hard on your hair. Hair Absorbs Water You don't need to actually make your hair wet (by swimming, showering, or washing it) for it to absorb moisture; your hair can take in moisture from the air. People actually use human hair to make hygrometers (instruments used to measure humidity). Your hair changes in a very predictable way when you expose it to changes in humidity. It is very simple - hair stretches when it's wet and contracts (shortens) when it's dry. This happens at an exact rate and is proportional to the amount of water in the air. This is what makes your hair so predictably difficult to manage when the weather is humid. Water is necessary to keep your hair clean, but it is hard on your hair by altering its structure and making it much more susceptible to damage.