Hair loss refers to  refers to a loss of hair from part of the head or body.
I thought only males lost hair, but I'm female and my hair is much thinner than it used to be.
It happens to the head
I think it happens elsewhere, too.  My dad is in his 80s, and he literally has NO hair on his legs anymore!
Oh well, one thing I am sure about is that hair loss can vary from a small area 
What causes us to lose hair?
of male-pattern hair loss is a combination of genetics and male hormones, the cause of female pattern hair loss is unclear, the cause of alopecia areata is autoimmune, and the cause of telogen effluvium is typically a physically or psychologically stressful event. Telogen effluvium is very common following pregnancy.
Less common causes of hair loss without inflammation or scarring include the pulling out of hair, certain medications including chemotherapy, HIV/AIDS, hypothyroidism, and malnutrition including iron deficiency. Causes of hair loss that occurs with scarring or
Hair loss
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Typically inflammation or scarring is not present. Hair loss in some people causes psychological distress.
Common types include: male-pattern hair loss, female-pattern hair loss, alopecia areata, and a thinning of hair known as telogen effluvium. The cause