Blood Donation FAQs

Expand the topics for answers to our Blood Donation Frequently Asked Questions.

Who may donate blood?
Generally, anyone in good health can donate. Make sure you do not have a cold, flu or sore throat at the time of donation. For more information visit our Am I Eligible? section.

How often can I donate?
You can donate whole blood every 56 days, platelets once a week up to 24 times a year, and red cells every 16 weeks.

I once tried to give blood but was told that my blood count was too low. Does that mean I can’t ever give blood?
Not at all. Healthy individuals, especially women, will have times when their blood count is low. Just because your blood count was a little low at one time does not necessarily mean that you are chronically anemic and cannot give blood. A simple blood test will be performed at the time of your donation to determine if you can donate. For more information on the minimum blood count levels required to donate please see the FAQ on Hemoglobin and Blood Count.

What can I do if I’m not eligible to donate blood?

Although an individual may be unable to donate, he or she may be able to recruit a potential donor. BloodCenter is always in need of volunteers to assist at blood drives or donor centers or to host a blood drive. In addition, financial donations are always welcome to support research that could lead to that next medical breakthrough.

Why was I unable to donate blood today?

A low blood count is the most common reason that potential donors are not able to donate (deferral). The blood taken prior to donation provides a hemoglobin value. You were deferred because your blood count (hemoglobin value) was below the lower limit of acceptability to donate, which is 13 gm/dl for men, and 12.5 gm/dl for women. 


What are the causes of a low blood count?  

Low blood counts can have a number of causes and they vary between women and men.


Causes for low blood count in women:

The most common cause of low blood count in women who are premenopausal, is iron deficiency caused by menstrual blood loss. Women of childbearing age have high iron requirements because of the extra iron needed for menstruation and pregnancy. Eating iron-rich foods may be sufficient to correct iron deficiency in some individuals; however, some women will need to take oral iron supplements in order to increase their blood count enough to donate blood. 

If you are a post-menopausal woman and not donating three or more times per year, your blood count may still be within the normal range for women, but not high enough to donate blood. Please note that the lower end of normal range for non-African-American women is 11.3 gm/dl and for African-American women is 10.5 gm/dl. If the test performed today indicated that your blood count is below normal range, you may need to see your personal physician for further testing to determine the cause of your low blood count.

Causes for low blood count in men:

If you are not donating three or more times per year, your deferral today indicates that you may have a medical condition which is causing your low blood count.  In men, a blood count below 13 gm/dl is considered anemic. Your personal physician can perform additional testing to confirm the cause of your low blood count and determine its cause.

What should I do to increase my blood count?

Taking an iron tablet can be beneficial in helping to replace the iron lost in the process of donating blood. Multivitamins with iron generally contain small amounts of iron, but can be sufficient if taken daily. There are also a number of stronger oral iron pills available over the counter at most drug stores. These pills replace the lost iron more rapidly and are generally less expensive than multivitamins. If you choose to take an oral iron tablet, your physician or pharmacist can provide more specific information about the advantages and disadvantages of different oral iron supplements, and help you decide which may be best for you.

Being deferred for low blood count does not mean that you can never donate blood again.

Why is iron important?
It is important to keep a healthy iron level so your body can build new red blood cells daily and also replace those you donate. Iron is also important for normal growth and development, energy level
and brain function.

Should I take an iron supplement?
Yes. Replace iron loss by taking an oral iron supplement daily for 60 days immediately following your blood donation. We recommend taking an over-the-counter (OTC) supplement or multivitamin containing 18mg of elemental iron per day.

How long does it take to restore iron post-donation?
Approximately 6 months or more with a healthy diet. 1-2 months with an iron supplement.

Can I overdose on iron?
No, if the iron supplementation is taken as recommended.

Are hemoglobin and iron the same thing?
No! Hemoglobin is the protein that functions within red blood cells to carry oxygen from the lungs to the rest of the body. Iron is an essential mineral important for the structure and function of hemoglobin and several other proteins in the body.

What is the difference between testing for hemoglobin and testing for iron?
Your hemoglobin level tells us how many red blood cells are circulating in your body right now, and how much will be left after you donate one unit of blood.

When iron is measured by ferritin level, it is an indicator of the body’s total iron stores and therefore your capacity to make more red blood cells to replace the ones you’ve donated.

Ferritin testing must be performed at a laboratory and cannot be performed at the time of your donation. Blood Centers are now evaluating how to utilize this test in assessing a donor’s ability to be a frequent blood donor.

How long does it take to give blood?
The process for whole blood donation usually takes about one hour. The blood collection itself is usually about 10 minutes. The donation process includes registration, a brief medical screening, blood collection and refreshments. Expect to spend about 1 1/2 hours for apheresis (platelet, red cells) collections.

I’m afraid of needles. Does giving blood hurt? 
Giving blood does not hurt. You might feel a pinch when the needle itself first goes into your arm. During that pinch, think about the patient –– maybe a young child, mother, or a grandparent –– who is counting on your donation. You may experience discomfort for a few seconds, but you’ll have the lasting reward of knowing you saved a life.

How often can I donate blood?
Time restrictions between blood donations are placed by the Food and Drug Administration (FDA) to keep you safe. You can donate whole blood every 56 days. You can donate more frequently if you donate platelets or plasma. You can donate red cells every 16 weeks.

How long until my blood is used?
All blood donations are processed and available for use between 24 and 48 hours following donation. Whole blood is processed into components (red cells, platelets, plasma). After processing, the red cells can be stored for 42 days. Plasma can be frozen and stored for up to 12 months. Platelets (from whole blood or by apheresis) expire after five days.

How long is blood good for?
Whole blood is only useful to patients for 42 days. After that, it “expires” and must be destroyed. Platelets (a particular blood cell that is collected in concentrated doses during apheresis donations) have a “shelf life” of only five days. This is why there is a constant need for blood and donors.

Is donating blood safe?

Donating blood is completely safe. You cannot contract any diseases from donating blood. A sterile kit is used once and thrown away. BloodCenter of Wisconsin is committed to the safety and comfort of donors.

What happens to my blood after it’s donated?
After your blood is collected, it is sent to BloodCenter of Wisconsin's labs for testing. The Food and Drug Administration (FDA) requires that all blood undergo a series of lab tests before it is given to patients. We perform 15 separate tests on blood. These include tests for sexually transmitted diseases, West Nile virus, hepatitis and other illnesses. If a unit of blood passes all of these tests, it is safe for use.

Is it safe to receive blood?
Yes. The blood supply is the safest it's ever been, especially since the implementation of nucleic acid amplification testing (NAT). NAT is a more sensitive gene-based test to screen the blood supply for HIV, hepatitis B and C. Fifteen tests (11 for infectious diseases) are performed on each unit of donated blood.

Why are you testing my donation for Babesia?

BCW is taking part in FDA research study on the Babesia parasite.

If you spend time outdoors or up north during Wisconsin summers, then you probably know about deer ticks. Their bites can be a nuisance for people and pets, and some deer ticks carry Lyme disease and Babesia.

On June 27, BloodCenter began screening blood donations for Babesia, as we participate in a clinical research study being led by the Food and Drug Administration to develop a new test for the parasite.

Babesia infects red blood cells and causes Babesiosis, which can be a severe, life-threatening disease in infants, elderly, people with weak immune systems and other serious health conditions. While many people who carry Babesia feel fine and show no effects, others can develop flu-like symptoms such as fever, body aches, nausea and fatigue.

Wisconsin is a prime spot for deer ticks, along with Minnesota and the northeast part of the United States. Babesia is the most commonly documented cause of transfusion-transmitted infection. Summer, and in particularly July, is when most cases of Babesia are reported.

“BloodCenter is taking part in this study, because ensuring the safety of our patients is our first and foremost priority,” says Dr. Jerome Gottschall, senior medical director at BloodCenter of Wisconsin.

What are the different types of donation?
Whole blood, apheresis (platelets, plasma, red blood cells) and autologous.

Who uses my blood?
Red blood cells may be used to help accident victims, surgical patients and people with anemia. Platelets may be used to treat leukemia and other cancer patients. Plasma is often necessary in the treatment of patients suffering from burns or shock.

What is the difference between donating whole blood and a blood component (platelets, plasma, red cells)?
Donating a component is very much like donating blood. The primary difference is that during a component donation, blood flows from a tube in your arm to a sterile chamber within an automation machine that separates the blood into various components. The needed components are collected, the remaining blood is returned to your body.

How will I feel after I donate?
Most people feel fine after donating blood. Your body makes new blood constantly, and the fluid you give will be replaced within hours. Eating a full meal before donating will help you feel strong afterwards. Drinking water and juices before and after donating also helps your body replenish lost fluids. Strenuous activity should be avoided for 12 hours after donating. If you have a hazardous or strenuous job, you should donate at the end of your work shift.

How long will it take to replace my blood?
The body will replace the fluid portion of your blood within 24 hours. It will take a few weeks to replace the red blood cells.

How long will it take to replace my iron?
Approximately 6 months or more with a healthy diet.  1-2 months with an iron supplement. Replace iron loss by taking an oral iron supplement daily for 60 days immediately following your blood donation. We recommend taking an over-the-counter (OTC) supplement or multivitamin containing 18mg of elemental iron per day.

How often can I give?
Whole blood donors may give once every 56 days in order to allow plenty of time to replenish their red cells. Double red cell donors can give every 116 days, and platelets donors can give once a week up to 24 times a year.

Is it true that 16-year-olds can now donate blood?
Yes. On September 1, 2008 BloodCenter of Wisconsin began accepting donations from 16-year-olds (with parental consent) who are in general good health and meet the general criteria to donate. By becoming a blood donor your son or daughter is showing great civic responsibility, maturity and a sense of community pride. Please refer to our height and weight chart on the Blood Donation for Students page to verify eligibility to donate.

Do other states allow 16-year-olds to donate blood?
Nearly 30 states (including Illinois, Iowa and Minnesota) have permitted blood donations from 16-year-old donors and many have been accepting those donors for years.

Why does BloodCenter of Wisconsin require parental consent forms for 16-year-olds but not 17-year-olds?

According to Wisconsin state statute, parental consent is required for 16-year-olds, but not 17-year-olds. Some schools require parental consent forms for 17-year-old donors, but BloodCenter of Wisconsin is not required by law to collect parental consent from 17-year-olds.

All 16-year-olds must have a parental consent form to donate at any donation site including:
  • Community blood drives
  • Donor centers
  • High school blood drives (16-year-olds donating at high school blood drives should return the signed form as directed by the blood drive coordinator. A new form is required each time a 16-year-old donates.)

Where can I obtain a parental consent form?
Parental consent forms are available from BloodCenter staff at all blood drives and donor centers. High school blood drives will receive copies of consent forms from a BloodCenter of Wisconsin Donor Recruiter prior to the scheduled drive date. Parental consent forms for 16-year-olds can also be downloaded from our website at

What form of identification (ID) is needed to donate?

The following forms of ID with a birth date and photo will be accepted:
  1. Driver’s license
  2. State-issued ID card
  3. Student identification card
  4. Passport, visa or green card

How can donors prepare for their blood donation?
Donors should get a good night’s sleep, eat a good meal and drink plenty of fluids in preparation for their donation.

How often can one give whole blood?

You can donate whole blood every 56 days or eight weeks, up to six times per year.

Why should I give blood?

This is a volunteer opportunity like no other. BloodCenter of Wisconsin is the only provider of blood to the community hospitals where you live and work. Medical technology has provided many life-saving discoveries over the years, but there is still no substitute for blood. In a medical emergency, often the most important element is the availability of blood.
Your blood donation can help:
  • Trauma victims
  • Surgery patients
  • Premature babies
  • People with anemia
  • Cancer patients
  • Many more

What does it mean to have a rare blood type?
The term “rare” means that the type occurs in only a few people. Some rare types only occur in 1 in 5000 people. Many rare types are unique to specific populations. For example, Vel negative blood is more common in Caucasians while U negative blood is more commonly found in African Americans.

Does this mean there is something wrong with my blood?
No. A person with a rare blood type does not have better or worse blood—it is just a genetic difference. And it means you are extremely special!

If it is a genetic difference, does that mean others in my family might also be rare?
Yes, especially your brothers and sisters. Please encourage them to donate also.

Why are rare donors needed?
Because some blood types are so rare, your donation may be somebody’s only hope for survival. Patients who need frequent transfusions because of certain diseases such as sickle cell disease, leukemia and other cancers are especially at risk.

What is ARDP?
ARDP is the American Rare Donor Program. It is based in Philadelphia where they maintain a nationwide database of rare donors.

What happens when I give permission to be an ARDP registered donor?
BloodCenter of Wisconsin will notify ARDP that we are registering a donor, for example, that is O Positive and U Negative. If another blood center needs O Positive U Negative blood, ARDP can check their database and see that we have a donor registered with that type. They will then contact us to see if we have blood available or can call a donor to donate.

Will I ever be contacted by ARDP?
No. BloodCenter of Wisconsin only provides ARDP with your blood type and donor number. No personal information is provided.

What happens after I join ARDP?
BloodCenter of Wisconsin will contact you occasionally to update your address. We may also contact you to donate if we get a request for your rare type and have no units available in inventory.

Can I continue to donate regularly or should I wait until my type is needed?
Please continue to donate regularly. We get many requests each day for patients across the country who are in immediate need of blood. If we have blood available in our inventory, we can ship it the same day.

What if I donate and my type isn’t needed?
If you donate blood and we do not have any requests for your type, your donation is frozen for use in the future. Blood can be specially frozen for up to 10 years.

What if I have a question about the letter I received or about being a rare donor?

A BloodCenter of Wisconsin staff member will be glad to help you, please call (414) 937-6205.

Returning Donor ?

Whole Blood Donation
You can donate today if your last donation was on or before:
Double Red Cell Donation
You can donate today if your last donation was on or before:

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