<unk>  is the loss of blood from the circulatory system.<unk>  can occur internally, where blood leaks from blood vessels inside the body or externally, either through a natural opening such as the vagina, mouth or rectum, or through a break in the skin.
The complete loss of blood is referred to as exsanguination, and desanguination is a massive blood loss. Loss of 10-15% of total blood volume can be endured without clinical sequelae in a healthy person, and blood donation typically takes 8-10% of the donor's blood volume.
Bleeding
Hemostasis
Wound healing
Coagulation
Swelling 
Thrombosis
Contractility
Noma causes