A hair straightener is a tool which is designed to straighten out the hair. There are a couple of different ways in which hair straighteners can work. A number of companies make straightening irons, while others make chemical hair relaxers; both irons and chemicals are designed to change the chemical structure of the hair. As you might imagine, a hair straightener can cause damage to the hair, and it is a good idea to use specialized hair products with hair straighteners to avoid such damage.

Hair irons are quite old, dating back to at least the 1700s. When many people think of hair irons, they visualize curling irons, which are designed to bring curl to the hair, but it is also possible to find flat irons or tongs. As the hair is heated, the hydrogen bonds in the hair relax, allowing people to set the hair into a desired style. By heating a hair straightener like tongs or an iron and passing hair through or under the straighter, people can create very straight, smooth hair.

Chemical straighteners are also quite old, although the early versions tended to cause hair and scalp damage. These chemicals also change the structure of the hair, allowing people to set a hair style. They typically work by being applied and left in for a set period of time before being removed. Depending on the chemicals used, the hair may relax into straightened look for a few hours, or a much more extended period of time.

Many salons offer professional hair straightening, which is supposed to last longer than treatments used at home. The advantage of going to a salon is that stylists are experienced with the damage which sometimes occurs to straightened hair, and they can take steps to avoid such damage, by applying moisturizing creams and other protective serums. A salon's staff will also offer tips for maintaining and styling the newly straightened look.

The most common problem with straightened hair is dryness, which can cause the hair to turn brittle. Applying moisturizing conditioners can help with this, as can washing in lukewarm to cold water to avoid drying out the hair with heat. Many companies also make straightening irons which are designed to minimize heat damage, using ceramic elements and other tools, and chemical straighteners often come with specialized conditioners to keep the hair healthy.

If you use a hair straightener too much, your hair may become brittle and thin. In this instance, you may have to lay off the hair straightener to allow your hair to recover, and it helps to use rich moisturizing formulas; you may also want to cut your hair short to get rid of the damaged hair.