The Difference Between Giving Blood Plasma and Platelets
, by Andrew Odgers, 10 min reading time
Types of donation
The difference between giving blood, plasma and platelets
Whole blood, plasma and platelets are three distinct types of donation that help different patients in different ways. Whole blood donation is the most common type, taking around 470ml of blood that is separated into its components after collection. Platelet donation collects platelets via apheresis and returns the rest of your blood, taking around 90 minutes. Plasma donation similarly retains only the plasma fraction. Each has its own eligibility criteria, donation interval and clinical application.
The three donation types compared
Whole blood, platelets and plasma: what each involves and who it helps
Whole blood donation
Whole blood donation is what most people picture when they think of giving blood. Approximately 470ml of blood is collected over 10 to 15 minutes through a needle in the inside of the elbow. The blood is then transported to a processing facility where it is separated by centrifuge into its three main components: red blood cells, plasma and platelets.
Red blood cells from whole blood donations can be stored for up to 35 days. They are used for patients who have lost blood through surgery, trauma, childbirth complications or conditions such as sickle cell disease and severe anaemia. A single whole blood donation can provide red cells for one patient, plasma for another and platelets for a third, potentially helping up to three different people.
Platelet donation via apheresis
Platelet donation is performed via apheresis, a process that draws blood from the donor, separates out the platelets using a cell-separation machine and returns the remaining blood components to the donor through the same needle or a second site. The procedure takes approximately 90 minutes. Donors typically give more platelet concentrate per session than would be extracted from a whole blood donation.
Platelets have a shelf life of just five to seven days, which makes platelet donors uniquely critical to the supply chain. Cancer patients undergoing chemotherapy, patients having major surgery and people with platelet disorders including immune thrombocytopenia depend on fresh platelet donations continuously. Platelet donors can give every two weeks, up to 24 times per year, making the cumulative impact of a regular platelet donor very large.
Plasma donation via apheresis
Plasma donation also uses apheresis technology to collect plasma while returning red blood cells and platelets to the donor. Plasma is the straw-coloured liquid component of blood that carries proteins, clotting factors, antibodies and nutrients. A single plasma donation typically collects 600 to 800ml of plasma.
Plasma has two distinct clinical uses. Fresh frozen plasma is used in direct transfusions for patients with clotting disorders or major haemorrhage. Plasma is also the raw material for manufacturing immunoglobulins, clotting factor concentrates and albumin. The UK imports a significant proportion of the plasma it uses for pharmaceutical manufacture, and increasing domestic plasma donation is a stated NHS priority.
Donation intervals and frequency
The intervals differ significantly by donation type. Whole blood can be donated every 12 weeks for men and every 16 weeks for women. Platelet and plasma apheresis donations can be made every two weeks. This means a regular platelet donor can donate up to 24 times per year compared to three or four whole blood donations for the same period.
Donors who are eligible and willing to give platelets or plasma regularly provide a substantially greater cumulative contribution to the supply than whole blood donors at the same level of commitment. The NHS actively recruits for apheresis donation given the critical shortage of platelet supply relative to demand.
Which type is right for you
Eligibility criteria differ between donation types. Platelet donation requires a higher platelet count and has specific requirements around recent medication use, particularly aspirin. Plasma donation has its own eligibility criteria including weight requirements that differ from whole blood. The donation centre can assess your suitability for each type at your appointment or when you contact the helpline.
Many donors give whole blood at standard intervals while also being tested for platelet or plasma donation suitability. If you are found to be a good candidate for apheresis donation, the centre will explain the process and book your first apheresis appointment. Switching from whole blood to platelet donation, or giving both types alternately, is possible and encouraged for eligible donors.
Blood type and the clinical impact of each donation
Blood type affects the clinical value of different donation types differently. For whole blood, certain types including O negative, A negative and B negative are in particularly high demand because they can be given to a wider range of patients in emergencies. For platelets, HLA compatibility between donor and recipient becomes increasingly important for patients who have received multiple transfusions. Plasma donation, particularly AB plasma, is universally compatible and in consistent demand.
Regardless of blood type, every donation of every type is needed. The NHS maintains a constant balance across all blood groups and donation types. No donor should feel that their blood type makes their contribution less valuable.
Ready to donate
Find out which type of donation suits you
Whether you give whole blood, platelets, plasma or all three, the NHS needs regular donors of every type. Book your appointment and ask about your options when you arrive.
Before choosing a donation type
Things to know before your first apheresis donation
Apheresis donation for platelets or plasma involves a longer session and slightly different preparation. Keep the following in mind.
- Platelet donations take approximately 90 minutes. Allow more time than for a whole blood appointment. Bring something to keep you occupied during the session.
- Aspirin must be avoided for 48 hours before platelet donation. Aspirin affects platelet function and donated platelets from donors who have taken it recently may not function correctly for recipients.
- Calcium levels can drop slightly during apheresis due to the anticoagulant used. Some donors experience tingling around the mouth or in the fingers. Inform the staff immediately if this occurs. Calcium supplements may be offered.
- Eligibility for apheresis is assessed separately from whole blood. Your platelet count, vein suitability and other factors are checked before your first apheresis session. Not all whole blood donors will be suitable for apheresis.
Whole blood, platelets and plasma all save lives in different ways, for different patients, at different stages of treatment. Understanding the differences helps donors make informed choices about which type of donation to offer, and potentially to contribute more frequently than whole blood alone would allow.
Our How often can you give blood guide covers the donation intervals for whole blood, platelet and plasma donation in full.
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Back to the Giving Blood Hub
This article is part of our complete giving blood knowledge base, covering eligibility, preparation, what happens on the day, recovery, types of donation and the science of why blood is so urgently needed.
Keep reading
Donation types, intervals and blood type guides
How often can you give blood covers all donation intervals. What blood type can give blood to anyone covers blood type compatibility. And What happens to your blood after you donate covers processing and clinical use.
Frequently asked
Blood, plasma and platelet donation questions
What is the difference between donating blood and donating platelets?
Whole blood donation collects 470ml of blood in 10 to 15 minutes. Platelet apheresis draws blood through a machine that separates and retains the platelets before returning the rest to you. It takes around 90 minutes but the physiological impact per session is lower as most blood components are returned.
How often can you donate platelets?
Every two weeks, up to 24 times per year. Platelets have a shelf life of just five to seven days and are in constant urgent demand, which is why the interval is much shorter than for whole blood.
What is plasma used for?
Plasma is used for direct transfusions in patients with clotting disorders or major haemorrhage, and as the raw material for manufacturing immunoglobulins, clotting factors and albumin. The UK imports significant quantities of plasma for pharmaceutical manufacture and domestic donation is actively encouraged.
Can I donate both blood and platelets?
Yes. Many donors give whole blood at standard intervals and also donate platelets. Some people alternate between the two types. Your eligibility for each type is assessed separately.
Which blood type is most needed for donation?
O negative is the most universally compatible blood type for red cells and is in highest demand. AB plasma is universally compatible and always needed. Every blood type is needed across the full supply and no donation is less valuable than another.
Does platelet donation hurt more than blood donation?
No. The needle used for apheresis is similar to that used for whole blood. The main difference is the duration. The session takes around 90 minutes rather than 10 to 15, but the physical experience of the needle is comparable.