Numerous diseases can cause a change in hair texture and volume. According to the U.S. National Library of Medicine and the National Institutes of Health, or NIH, the lips, palms and soles of the feet are the only parts of the body on which hair does not grow. The NIH states that hair loss, infections and flaking are among the most common problems associated with the hair and scalp, although there are also certain medical conditions in which the texture of a person's hair changes.
Hypothyroidism is a disease that can cause a change in hair texture. According to the National Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK--a division of the National Institutes of Health--hypothyroidism occurs when the thyroid gland is unable to produce enough thyroid hormones to meet the body's needs. One of the most common signs or symptoms associated with hypothyroidism is dry, thinning and coarse hair. Other common symptoms of this disease include fatigue, weight gain, face puffiness, an inability to tolerate the cold, muscle and joint pain, constipation, reduced sweating, depression and a decreased heart rate. The NIH states that thin, brittle hair and fingernails are among the early symptoms of the disease. A person with hypothyroidism may notice an increased amount of hair loss when washing her hair in the shower.
Hirsutism is a condition that can cause a change in hair texture. The Mayo Clinic website states that hirsutism is a condition of unwanted, male-pattern hair growth in women. Approximately 10 percent of American women have some level of hirsutism. Hirsutism is believed to be caused by diseases that stimulate the production of male hormones known as androgens. Hirsutism may also be a family or ethnic trait, notes the Mayo Clinic website. Hirsutism is characterized by excessive amounts of coarse and pigmented hair on body parts that do not typically experience hair growth in women, such as the face, back and chest. Along with the excess hair growth and coarser hair, a deepening voice, balding, acne, reduced breast size, clitoris enlargement and increased muscle mass are common symptoms associated with hirsutism. Although there are no hirsutism-related physical complications, the chemical imbalances that cause hirsutism should be assessed by a qualified physician.
Anorexia nervosa is a disease that can cause changes in hair texture. According to the Family Doctor website, anorexia is a disease that usually occurs in teenage girls, although it can develop in teenage boys and adults of both genders. A person who is anorexic is obsessed with being thin, loses a significant amount of weight and is extremely fearful of gaining weight. An anorexic believes she is overweight even though she may be very thin. The Family Doctor website states that anorexia is more than simply a problem with food or weight: it's a way to use food and weight to manage emotional turmoil or upheaval. Anorexics typically have dry skin and thinning hair on the head. Other common health problems associated with anorexia include cold intolerance, depressed immune system and frequent illness, irritability, inability to concentrate and loss of menstrual periods in women.