Blood Type Test

Also known as: ABO Blood Grouping Test, ABO/Rh Typing, Blood Group Test
Updated: August 6, 2026

Quick Guide

The ABO and Rh test identifies your blood type from a standard blood draw. It classifies your blood into one of eight types: A+, A-, B+, B-, O+, O-, AB+, or AB-. A CLIA-certified (Clinical Laboratory Improvement Amendments) lab processes the sample.

If you’re heading into surgery, starting prenatal care, or planning to donate blood, knowing your blood type is a practical first step. No fasting or special prep is needed. The blood draw takes a few minutes. Results delivered to your secure online account. If you’ve never had your blood type on record, this test gives you a permanent answer you can share with any provider.

About the Blood Type Test

Purpose of the test

The ABO and Rh test tells you which blood type you have and whether you carry the Rh factor. Three situations call for it most often: blood transfusions, pregnancy care, and organ or bone marrow transplant evaluation.

Receiving incompatible blood can trigger an acute hemolytic transfusion reaction (AHTR), where your immune system attacks the transfused red blood cells. In severe cases, that reaction can cause kidney failure, according to the MedlinePlus blood typing overview. If you’re heading into surgery or need a transfusion, your blood type must be confirmed first.

If you’re pregnant or planning a pregnancy, knowing your blood type is part of standard prenatal care. An Rh-negative result means your provider will watch for Rh incompatibility with the fetus. Early detection lets your provider prevent complications with Rh immune globulin (RhoGAM) at the right times.

The standard ABO and Rh test doesn’t detect other blood group antigens like Duffy, Kell, or Kidd. It doesn’t diagnose any medical condition on its own. It won’t assess hemoglobin levels, platelet counts, clotting factors, or blood disorders. Those need different testing.

What does the ABO and Rh test measure?

The test covers two markers from a single blood sample.

  • ABO Blood Group (ABO): Shows which of four blood groups (A, B, AB, or O) you belong to based on antigens on your red blood cells.
  • Rh Factor (Rh): Shows whether the Rh (D) protein is present on your red blood cells, classifying you as Rh-positive or Rh-negative.

The lab uses an agglutination typing technique. It mixes your blood with anti-A and anti-B serums to see which causes red blood cells to clump (forward typing). Then it cross-checks by mixing your serum with known A and B red blood cells (reverse typing). For Rh typing, the lab mixes your blood with anti-D serum and looks for clumping. Two independent checks verify your ABO group before a result is reported.

When should I get a blood type test?

Consider testing if any of these apply:

  • An upcoming surgery or procedure that may need a blood transfusion
  • A current or planned pregnancy, especially at your first prenatal visit
  • Interest in donating blood, organs, or bone marrow
  • No record of your blood type in your medical history
  • A family member who needs a compatible blood or organ donor
  • Emergency preparedness planning

For routine screening, blood typing is standard in these situations:

  • Pregnant people, at the first prenatal visit
  • Rh-negative pregnant people in a second pregnancy where the father is Rh-positive or unknown, to guide monitoring and possible RhoGAM treatment
  • Anyone scheduled for surgery where blood loss is possible
  • All blood donors, typed automatically at donation
  • Organ, tissue, or bone marrow transplant candidates and donors

How It Works

How to get tested

You can order the Blood Type Test (ABO Grouping and Rh Typing) yourself online, with no doctor visit or referral needed. A licensed physician reviews and authorizes your order as part of the process. Most results are ready in one to three business days after the lab receives your sample and appear in your secure online account.

Before the test

No fasting or special prep is needed. Red blood cell antigens are stable. They aren’t affected by food, medications, or time of day.

Tell the lab staff if you’ve had a recent blood transfusion or bone marrow transplant. A transfusion may temporarily mask your true blood type. A transplant from a donor with a different blood type can change your ABO or Rh result. The lab needs that context to read your result correctly.

Bring a photo ID and any paperwork from your provider.

During the test

  1. Check in at the lab. A phlebotomist reviews your ID and order.
  2. A tourniquet goes around your upper arm. The phlebotomist cleans a spot on your arm with an alcohol wipe.
  3. A needle goes into a vein, usually in the crook of your arm. You’ll feel a brief pinch.
  4. One small vial of blood is collected. The draw takes two to three minutes.
  5. The phlebotomist removes the needle and covers the site with a small bandage.

Keep the bandage on for at least 15 minutes. You can leave right away. There are no activity restrictions.

Some people notice light bruising at the draw site over the next day or two. That’s normal. Call your provider if you see swelling, lasting pain, or signs of infection.

After the test

Results are typically ready within one to three business days after the lab receives your sample, though timing can vary by lab. Your result comes delivered to your secure online account. Emergency blood typing in a hospital lab is usually available within minutes.

Once you have your result, record it somewhere you can find it: your medical records, an emergency contact card, or a medical ID. Blood type is inherited, so siblings and children may share compatible types. It’s worth sharing with family.

What Do My Results Mean?

Your result shows two things: your ABO blood group (A, B, AB, or O) and your Rh type (positive or negative). Together, they give you one of eight blood types.

Understanding your ABO blood group result

Your ABO group depends on which antigens your red blood cells carry:

This matters for transfusions. If you’re group A, your blood carries anti-B antibodies. Receiving type B blood would trigger your immune system to attack the transfused cells. Group O red blood cells carry no A or B antigens, so they don’t trigger that reaction in any recipient, which is why, as the MedlinePlus explains, type O blood can be given to anyone with any blood type.

According to the American Red Cross, the universal red cell donor has type O negative blood, and the universal plasma donor has type AB blood. These rules apply to red blood cell transfusions only. Plasma and platelet transfusions follow different compatibility rules.

Before any transfusion, a crossmatch is performed:

  • Major crossmatch: Checks whether the recipient has antibodies against the donor’s cells
  • Minor crossmatch: Checks whether the recipient’s red blood cells trigger antibodies in the donor’s blood

Understanding your Rh factor result

Rh-positive means the Rh (D) protein is on your red blood cells. Most people are Rh-positive. Rh-negative means it isn’t there. Rh-negative blood is completely healthy on its own.

Rh status matters most during pregnancy. As MedlinePlus explains, if you are pregnant and Rh-negative and your fetus is Rh-positive, your body will react to the fetus’s blood as a foreign substance and create antibodies that can damage the baby’s red blood cells. The first pregnancy often goes fine. But those antibodies can cross the placenta in a later Rh-positive pregnancy and attack the baby’s red blood cells. This causes Hemolytic Disease of the Fetus and Newborn (HDFN), which involves severe anemia, jaundice, and in serious cases, heart failure.

RhoGAM prevents this. According to Mayo Clinic, if you haven’t started to produce Rh antibodies, you’ll likely need a shot of Rh immune globulin to prevent your body from producing them during pregnancy. Rh-negative pregnant people typically get an injection between 26 and 28 weeks, and again within 72 hours after delivery if the newborn is Rh-positive. Mayo Clinic also notes that Rh immune globulin is recommended after miscarriage, ectopic pregnancy, amniocentesis, or any bleeding event during pregnancy. Talk with your provider about the timing that fits your situation.

What your combined blood type means

According to the American Red Cross, only 7% of the population are O negative, yet the need for O negative blood is the highest because it is used most often during emergencies, while O positive is the most frequently occurring blood type at 37% of the population. AB- is the rarest of the eight common types. The distribution varies somewhat by ancestry. These compatibility rules apply to red blood cell transfusions only.

How We Make Testing Easy

No doctor required

Order the test you want yourself, without a referral or insurance.

Certified lab quality

Samples are processed at accredited labs that meet national clinical standards.

Thousands of U.S. lab locations

Find a lab near you to give your sample.

Fast online results

Most are ready to view securely within a few business days.

Your results stay private

They reach you alone, not your insurer or your medical record.

Upfront pricing

Know the full cost before you order, with no surprise bills.

Sources Image 871
  1. MedlinePlus. Blood Typing. MedlinePlus. 2024.
  2. MedlinePlus. ABO Incompatibility.
  3. MedlinePlus. Rh Incompatibility. MedlinePlus. 2025.
  4. American Red Cross. Facts About Blood and Blood Types.
  5. Mayo Clinic. Rh Factor Blood Test.
  6. National Heart, Lung, and Blood Institute. Blood Tests. NHLBI, NIH.

Frequently Asked Questions

  • Why is knowing my blood type important?

    Your blood type determines which donated blood is safe for you. An incompatible transfusion can trigger hemolysis (destruction of red blood cells), which can damage the kidneys. Blood type is also essential for pregnancy care, organ transplants, and blood donation eligibility.

  • Rh-negative blood is completely healthy. It only becomes a concern during pregnancy or if you receive Rh-positive blood. If you’re Rh-negative and pregnant, your provider will monitor for Rh incompatibility and discuss whether RhoGAM is right for you.

  • Yes. O-negative (O-) is the universal donor for red blood cell transfusions because O- cells carry no A, B, or Rh antigens. AB-positive (AB+) is the universal recipient because the immune system recognizes all three antigens as its own. These rules apply to red blood cells only, not plasma or platelets.

  • No. The ABO and Rh test identifies only the eight common blood types. Other blood group systems exist, including Duffy, Kell, Kidd, and Lutheran. People with complex transfusion needs, like those with sickle cell disease, may need extended red cell antigen typing, as described in the NHLBI’s overview of blood tests.

  • It’s genetic and generally doesn’t change. One exception: a bone marrow transplant from a donor with a different blood type can lead to a blood type change over time. The donor’s stem cells start producing red blood cells with different antigens.

  • You inherit one ABO gene from each biological parent. ABO follows codominant inheritance, meaning both A and B alleles show up when present. That’s why AB is a possible type. The O allele is recessive, so you need the O gene from both parents to be type O. Rh follows dominant inheritance: one copy of the Rh-positive gene is enough to make you Rh-positive.

  • Yes. Hospitals always run independent blood typing before a transfusion. It’s a safety protocol. Knowing your blood type is useful for personal knowledge and emergency communication, but it doesn’t replace pre-transfusion verification.

  • No. You can eat and drink normally before your appointment.

  • No. Your results go to your secure online account and are not shared with anyone else. You can download or print them to share with your own doctor if you choose.

  • We do not bill insurance directly, which keeps your testing and results private. You can pay with HSA or FSA funds, and we can provide an itemized receipt if you want to request reimbursement.

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