Alopecia areata is a common condition that causes hair loss. In alopecia areata, inflammation results from the immune system erroneously attacking hair follicles. Although scientists are unsure of the exact source of the immunological attack on hair follicles, they do think that both hereditary and environmental (non-genetic) variables are involved. For alopecia areata, there are treatments provided at Sanjay Rithik Hospital that can help to improve the appearance of the hair. Alopecia areata starts when? Alopecia areata can strike at any age, although it usually strikes by the time a person reaches their 30s. According to the National Institutes of Health, it affects approximately 4.7 million people in the United States.