It seems like you're asking about why human hair falls out. There are many reasons why this happens, including:
* Normal hair growth cycle: Every hair goes through a cycle of growth, rest, and shedding. This is a natural process and it's normal to lose some hair each day.
* Hormonal changes: Changes in hormones, such as during pregnancy, menopause, or thyroid disorders, can affect hair growth.
* Stress: Stress can cause hair loss in some people.
* Medical conditions: Certain medical conditions, such as alopecia areata, can cause hair loss.
* Medications: Some medications, such as chemotherapy drugs, can cause hair loss.
* Nutritional deficiencies: Lack of certain nutrients, such as iron or zinc, can contribute to hair loss.
* Hairstyles: Tight hairstyles, such as braids or ponytails, can pull on the hair and cause breakage.
* Chemical treatments: Chemical treatments, such as hair dye or perms, can damage the hair and lead to breakage.
If you are concerned about hair loss, it's best to consult a doctor or dermatologist to determine the underlying cause and discuss treatment options.