• Family History (heredity)
• Hormonal changes and Medical conditions. Medical conditions include alopecia areata, which causes patchy hair loss, scalp infections such as ringworm and a hair-pulling disorder called trichotillomania.
• Medications and Supplements. Hair loss can be a side effect of certain drugs.
• Radiation Therapy to the Head. The hair may not grow back the same as it was before.
• A Very Stressful Event. Many people experience a general thinning of hair several months after a physical or emotional shock.
• Excessive Hairstyling or hairstyles that pull your hair tight, such as pigtails or cornrows, can cause a type of hair loss called traction alopecia.