The immune system, which includes bone marrow, thymus, spleen, lymph nodes and the white blood cells, functions to recognize and eliminate foreign invaders. When the immune system fails to differentiate between foreign invaders and normal healthy cells, autoimmune disease results. About 80 to 100 autoimmune diseases have been identified, affecting 23.5 million Americans. Autoimmune diseases are considered a major health problem, according to American Autoimmune Related Diseases Association. Autoimmune diseases can affect every part of the body, producing a wide range of symptoms, including hair loss.
Alopecia areata describes an autoimmune disease caused by the body's immune system attacking the hair follicles. When white blood cells attack hair follicles, they interrupt hair growth leading to small round patches of hair loss. Alopecia areata affects approximately 2 percent of the United States population, most frequently children and young adults, according to the American Academy of Dermatology. In addition to scalp hair loss, alopecia areata can cause a loss any other hair, including the eyelashes, eyebrows and facial hair. The unpredictability of this autoimmune disease makes it frustrating, but because the hair follicles remain alive, hair regrowth can occur at any time, even after years of baldness.
Lupus, a chronic autoimmune disease, affects approximately 1.5 million Americans, according to the Lupus Foundation. Although the exact cause of lupus remains a mystery, because lupus tends to occur within families, doctors know that genetics plays a role. Those born with a susceptibility for developing lupus then need an environmental trigger, such as exposure to sun, an infection, or hormone changes such as occur with pregnancy, to develop the disease.
Lupus affects many different systems and organs in the body, creating a wide range of symptoms. Common symptoms include fatigue, headache, painful joints, anemia, abnormal blood clotting, and hair loss. Because these symptoms occur in many different disorders, lupus is often referred to as the "great imitator," according to the Lupus Foundation, making it difficult to obtain a definite diagnosis.
Hashimoto's disease, also known as chronic lymphocytic thyroiditis, occurs when the cells of the immune system attack the thyroid gland. The thyroid gland, located in the neck, produces hormones that regulate many of the body's activities. The immune system attacking the thyroid gland causes inflammation of the gland, which interferes with its ability to function, resulting in an underactive thyroid. Hashimoto's disease is the most common cause of hypothyroidism in the United States, according to MayoClinic.com.
Hashimoto's disease progresses slowly, producing few symptoms until the level of thyroid hormones drops significantly. Initial symptoms include fatigue and sluggishness. Additional symptoms, such as hair loss, increased sensitivity to cold, puffy face, hoarse voice, unexplained weight gain and muscle aches increase in severity if the condition remains untreated.