Hair shaft defects can be inherited or acquired, and sometimes may indicate underlying disease. An association of a hair anomaly with other abnormalities, especially those affecting skin, teeth and nails, is seen in many congenital syndromes. Physical or chemical injury may causes various hair shaft abnormalities, both in normal or in fragile hair. To the lay person, hair shaft defects manifest as funny-looking or poorly growing hair, which causes great parental concern. Fortunately, hair shaft defects are not common and account for only 1% of all hair disorders.