Well some women do, I think your referring to a female when they get their period. It's normal for the female body to lose that much blood a month. But some women bleed more than they should and that is when they start losing more blood than they should. Like myself, my blood level was 1, I was tired and groggy and always sick, I needed a transfusion, which my blood only went up to 4, which is anemic. So some women have it worse than others.
Why do you specifically mention women? Why would a women be losing blood? And what amount, and...... how? And if the question was *Why don't people die from losing a great amount of blood?* It's because we recieve blood transfusions, or just faint and slowly recuperate with time.
What you mean about losing blood is their monthly period or menstruation? If so, it's a normal response of the body for women. It should serve as a part of pregnancy but if not used it will be expelled by the body every month.
Percentage wise the amount of blood lost monthly is not very high. Lost blood is also replaced very rapidly naturally. You lose more blood during a donation at a blood bank in a few minutes than during your period, and you get up and carry on your life just fine.