What is the reason for hair loss?

Hair loss can be a result of hormonal changes, medical conditions, such as thyroid problems, scalp infections and certain medications used to treat diseases, according to Mayo Clinic. Hair loss can also be attributed to hereditary conditions, states WebMD.

Sudden hair loss is typically attributed to medical conditions, according to WebMD. Some of the most common conditions include pregnancy, anemia, autoimmune diseases and skin conditions, such as dermatitis or psoriasis.

Menopause, extreme stress, such as mental or physical trauma, and intense illnesses may also cause temporary hair loss, according to WebMD. In these cases, hair typically grows back once the causing condition ends.