Other causes of hair loss, especially if it is in an unusual pattern, include: 1  Alopecia areata (bald patches on the scalp, beard, and, possibly, eyebrows; eyelashes may fall out). 2  Anemia. 3  Autoimmune conditions such as lupus. 4  Burns. Certain infectious diseases such as syphilis.  Excessive shampooing and blow- 1 drying. Hormone changes.  Thyroid diseases.