Stress

Stress can be a major factor in many physical problems, including hair loss. Events such as divorce, death of family or friends or social pressure can create a great amount of stress on a young person.

Medications

Certain medications may cause hair loss. Mood disorder medications, acne medications and diet pills are a few that can contribute to hair loss in a young girl.

Traction Alopecia

Traction alopecia is a condition where tight hairstyles, such as ponytails or braids, can cause enough stress on the root of the hair that it becomes weak, and the hair falls out.

Underlying Illness

Hair loss can be a sign of a serious condition, such as polycystic ovary syndrome, which is common in young girls; endocrine disorders; lupus and diabetes. Sometimes hair in a growth phase will revert to a resting phase following an illness; hair loss occurs a month or two later even though the person has recovered.

Alopecia areata

Alopecia areata is an autoimmune disease in which a person's own immune system attacks healthy hair follicles. Small round bald spots may appear on the scalp and then spread. Often the hair will grow back within a year, but sometimes hair loss recurs.

Trichotillomania

People with trichotillomania have a psychological disorder, which involves repeatedly pulling their own hair out. Most people who have trichotillomania need professional therapy to learn to control this behavior.

Source:

Kidshealth.org

Hair-loss-advisor.com

Vzbotanicals.com

Resource:

Teengrowth.com