As a rule, patients are not transfused with blood proper, but with certain specific components that it needs. Therefore, and take away from the donor can not all the blood, but only its components.
Types of blood donation
1. Delivery of whole blood. At a time the donor is taken from 400 to 500 ml. The procedure for taking whole blood lasts only 5 - 10 minutes. After giving blood, it should take at least 60 days for the donor to be able to donate blood again. Women are recommended to donate blood no more than 4 times a year, men - no more than 5.
Delivery of blood components:
When the donor donates blood components, howrule, first take whole blood, filter it in a special way (i.e., separate the desired component), and what remains is poured back to the donor.
2. Delivery of plasma (plasmapheresis). For 1 time take about 400 ml. blood. Between blood donation and plasma donation should take at least 30 days. After delivery of plasma, whole blood can be taken in 14 days, and after 14 days it is possible to give up plasma again. In a year the donor can take up to 12 liters of plasma.
3. Delivery of platelets (thrombocytopheresis). This procedure is more complicated and requires special preparation of the donor. The collection of platelets is carried out on special devices and can last more than an hour. The periods between the delivery of platelets are exactly the same as in the case of delivery of plasma.
4. Delivery of granulocytes. Granulocytes are leukocyte derivatives. But it is worth noting that this type of blood sampling is very rare and is performed in exceptional cases. After 4 regular hemorrhage, doctors recommend taking a break 3 months.
Now you know how often you can donate blood. Please, please, these terms, and then you can help people and do not hurt yourself.