Your blood type, or blood group, is decided by the genes you inherit from your parents. Find out why being given the wrong type of blood can be very dangerous.
Blood and blood vessels
Blood flowing through the blood vessels carries oxygen, nutrients and waste around the body. Find out the components of blood.
Conception is complex – there is often more to it than just having sex. Learn more about ovulation, pregnancy and your growing embryo.
A heart transplant is an operation to replace a damaged heart with a healthy donor heart. Learn about waiting lists and life after a transplant.