Sudden hair loss can occur as a result of hormonal factors, medical conditions, certain medications, hairstyles and shock. Hair loss usually ceases after the condition is resolved, says Mayo Clinic.
Temporary hair loss can occur due to hormonal changes and imbalances. These changes can be caused by pregnancy, childbirth, discontinuation of birth control pills or onset of menopause, according to Mayo Clinic. Problems with the thyroid can cause hair loss as the gland helps regulate hormone levels in the body. Alopecia areata is a disease that causes the body's immune system to attack hair follicles. It can be recognized by smooth, circular bald patches. Scalp infections, like ringworm, can cause hair loss. Once treated, hair usually grows back.
Medications used to treat cancer, arthritis, depression, heart problems and high blood pressure can cause hair loss, claims Mayo Clinic.
Physical or emotional shock, caused by high fevers, excessive weight gain, or death of a family member can cause hair loss months after they occur. Hair loss can also occur if hair is pulled tight into hairstyles like pigtails or cornrows, reports Mayo Clinic.
If the hair does not grow back, there are several medications available to treat the loss. Minoxidil, also known as Rogaine, is an over-the-counter liquid or foam that can be rubbed into the scalp to grow hair and prevent further loss, says Mayo Clinic. Hair transplants can also be used to replace lost hairs.