On average a healthy person sheds 50 to 100 hairs a day, which usually doesn’t cause noticeable thinning of scalp hair because new hair is growing in at the same time with comparable speed. Hair loss occurs when this cycle of hair growth and shedding is disrupted or when the hair follicle is destroyed and replaced with scar tissue.
The exact cause of hair loss may not be fully understood, but it’s usually related to one or more of the following factors:
- Family history (heredity)
- Hormonal changes
- Medical conditions