Final answer:
Lochia is a postbirth uterine vaginal discharge consisting of uterine lining cells, blood cells, and debris. It changes from thick and dark red to lighter pink, and finally to white or creamy, as the postpartum period progresses.
Step-by-step explanation:
Lochia is a postbirth uterine vaginal discharge that occurs after giving birth. It is made up of uterine lining cells, blood cells, and other debris. Initially, the discharge is thick and dark red, known as lochia rubra, which lasts for 2-3 days. This is followed by a lighter pink discharge, called lochia serosa, which continues until about the tenth postpartum day. Finally, a white or creamy discharge, known as lochia alba, may continue for 1-2 weeks after childbirth.