drying of hair image by Arkady Chubykin from Fotolia.com

Dry hair is coarse, unruly hair that shows signs of damage such as brittleness, split ends and breakage. It's caused by a lack of natural oils produced by your scalp to keep your hair soft. Although your hair may be naturally dry and coarse, excessively dry hair can be a sign of a health issue, use of harsh hair products or excessive washing.

Health Issues

diet and health image by Photoeyes from Fotolia.com

A lack of vitamins and nutrients in your diet can lead to weak, brittle hair. Protein is an important nutrient found in animal meat, beans and whole grains, and it contributes to strong, healthy hair. A lack of it in your diet can lead to weak hair and nails. According to the New York Times, an underactive thyroid gland (hypothyroidism) can also lead to dry hair. A visit to your doctor is required for prescription medication to treat your disorder.

Harsh Hair Products

shampoos and shaving foam lined up image by Georgios Alexandris from Fotolia.com

Harsh shampoos that contain sodium lauryl sulfate, a strong detergent, can strip your hair of moisture and lead to dry hair. Over time, the hair becomes coarse and is prone to breakage. Washing your hair every day can also cause dry, coarse hair; it doesn't have a chance to create natural oils that keep your hair moisturized. Wash your hair every other day rather than every day, and use a deep conditioner once a week to help restore moisture.

Heat Styling

dryers image by timur1970 from Fotolia.com

Excessively styling your hair with a blow dryer or flat iron can also deplete your hair of natural oils. Reduce your heat styling to one to two times a week to reduce damage. Protect your hair before heat styling by coating it with a thermal protectant spray.