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Aborhbld

Published: August 9, 2026Updated: August 16, 2026

This test determines your blood type (A, B, AB, or O) and Rh factor (positive or negative), which are essential for safe blood transfusions and pregnancy management.

Quick summary

{"Your blood type is determined by antigens on the surface of red blood cells","The test is essential before blood transfusions, surgery, or pregnancy","Rh-negative mothers may need special care during pregnancy to prevent complications","Knowing your blood type can help in emergency medical situations","A simple blood draw is all that is needed for this test"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
882-1
Short code
ABORH
Synonyms
ABO + Rh Bld
Category
chemistry
Sample
whole-blood
Container
EDTA lavender-top tube (K2 or K3)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Gel column agglutination or tube agglutination technique
CPT
86900
SNOMED
112144004
Specimen volume
3-5 mL whole blood
Stability
Room temperature (20-25°C): 72 hours; Refrigerated (2-8°C): 7 days; Do not freeze
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
1–24 hours
Order
routine

What is this test?

The ABO and Rh blood type test is a routine laboratory test that identifies your blood group and Rh factor. Your blood type is determined by the presence or absence of specific antigens (A and B) on the surface of your red blood cells. The Rh factor is another protein that can be either present (Rh-positive) or absent (Rh-negative). Together, these determine your blood type: A positive, A negative, B positive, B negative, AB positive, AB negative, O positive, or O negative.

How is the test performed?

A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. This whole blood sample is then sent to a laboratory where it is tested with special antibodies to determine how your red blood cells react. The test is quick, typically taking only a few minutes to collect the sample. Results are usually available within a day or two.

Why is it important to know your blood type?

Knowing your blood type is crucial for several medical situations. If you ever need a blood transfusion, receiving the wrong blood type can cause a life-threatening immune reaction. During pregnancy, if a mother is Rh-negative and her baby is Rh-positive, it can lead to complications in current or future pregnancies. Surgeons also need to know your blood type before any major operation. Additionally, some people believe blood type may influence certain health traits, though this is not scientifically proven.

Reference range

Results reported as ABO group (A, B, AB, or O) and Rh type (positive or negative) - this is a categorical test with no numerical reference rangeN/A

Specimen: whole-blood

No fasting required. Ensure proper patient identification using two patient identifiers per laboratory protocol. Collect specimen prior to transfusion if patient has recently received blood products. Inform laboratory of recent transfusions or bone marrow transplant as these may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Do I need to fast before this test?
No, you do not need to fast before an ABO and Rh blood type test. You can eat and drink normally before the test. However, always follow any specific instructions given by your healthcare provider.
Does the blood draw hurt?
You may feel a brief pinch or sting when the needle is inserted into your arm. This sensation usually lasts only a moment. Some people may experience mild bruising at the puncture site afterward, which typically resolves within a few days.
How long does it take to get results?
Results from an ABO and Rh blood type test are typically available within 24 to 48 hours, though some laboratories can provide results the same day. Your healthcare provider will inform you when your results are ready.
What happens if I need a blood transfusion?
Before any blood transfusion, the hospital will verify your blood type to ensure you receive the correct blood type. This double-checking process is a critical safety measure to prevent life-threatening reactions.
Can my blood type change over time?
No, your ABO and Rh blood type does not change throughout your lifetime. It is determined at birth and remains constant. However, in extremely rare cases, certain bone marrow transplants or medical conditions might temporarily affect blood type testing results.
  1. 1
    Mayo Clinic - Blood TypingSource
  2. 2
    American Red Cross - Blood TypesSource
  3. 3
    MedlinePlus - Blood TypesSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy