Dry hair is a relative symptom.
Dry hair may be described as hair with insufficient moisture and oil content to maintain a normal sheen and texture. Dry hair may result from excessive washing, harsh detergents , a dry or hostile environment, inadequate diet, or underlying disease states. Abnormal hair texture, sheen, and even abnormal hair color may be seen in various states of malnutrition such as kwashiorkor and marasmus. Metabolic diseases such as hypothyroidism and Menke's kinky hair syndrome produce brittle dry hair. This list is not all inclusive, and the causes are not presented in order of likelihood.