Blood Products for Hemophilia:
Platelets
Platelets are cell fragments produced from megakaryocytes.
Blood normally contains 150,000–350,000 per microliter (µl) or cubic millimeter (mm3). This number is normally maintained by a homeostatic (negative-feedback) mechanism.
If this value should drop much below 50,000/µl, there is a danger of uncontrolled bleeding because of the essential role that platelets have in blood clotting.
Some causes:
certain drugs and herbal remedies;
autoimmunity.
When blood vessels are cut or damaged, the loss of blood from the system must be stopped before shock and possible death occur. This is accomplished by solidification of the blood, a process called coagulation or clotting.