Hair extensions are lengths of either real or synthetic hair that can be affixed close to the scalp through a number of systems. When well matched in color and texture, and professionally applied by a competent extensionist, hair extensions mix in and move naturally with your own hair, making it difficult to tell you are wearing them. They can provide volume, extend hair, and add highlights or lowlights without the harshness of coloring your own hair. Some extensions can be worn continuously for up to 3 months before requiring maintenance.

Hair extensions come in many colors, textures, styles and lengths to match any hair type. Natural or human hair extensions are more expensive because they can be colored, set, curled or treated. Synthetic hair will melt if exposed to the high temperatures of a curling iron or a hot blow dryer; it is used as purchased, and is generally not recommended. Synthetic extenders are available widely at department stores. Human hair extensions are generally purchased through salons that provide extensionist services.

Hair extensions have become very popular in the last 10 years with many celebrities taking advantage of the instant volume and length. Jennifer Aniston, Sandra Bullock, and Nicole Kidman are just a few famous women who have worn hair extensions.