• Genetics: Hair loss can be hereditary, meaning it's passed down from parents 

• Hormonal changes: Pregnancy, childbirth, menopause, and other hormonal changes can cause hair loss 

• Medications: Certain medications, such as blood pressure pills, antidepressants, and birth control pills, can cause hair loss 

• Stressful events: Major illnesses, surgery, and other stressful events can cause hair loss 

• Nutritional deficiencies: A lack of iron, protein, biotin, folate, or vitamin B12 can cause hair loss 

• Hairstyles and treatments: Tight hairstyles, perms, bleaching, and other hair treatments can damage hair and cause loss Other causes of hair loss include: 

• Thyroid disease

• Fungal infections

• Radiation therapy

• Skin problems

• Hair growth disorders

• Internal diseases

• Cancer treatment

• Weight loss

It's normal to lose 50–100 hairs a day, but hair loss can sometimes be a sign of an underlying medical condition. Some types of hair loss are permanent, while others may be temporary.