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Red Blood Cell Clumping (RBC Clumping) Screening Test

Published: August 9, 2026Updated: August 17, 2026

This test checks for abnormal clumping of red blood cells, which may indicate underlying conditions like autoimmune disorders or certain infections.

Quick summary

["Clumping of red blood cells can affect blood flow and may signal a need for further medical evaluation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
53360-4
Short code
RBC clumps # Ur Comp Assist
Synonyms
RBC clumps # Ur Comp Assist
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
computer-assisted
CPT
85041
SNOMED
900000000000003001
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like fatigue, pale skin, joint pain, or unexplained bruising. It can also be part of routine blood work to monitor conditions like anemia or autoimmune diseases.

What Does Clumping Mean?

Normal red blood cells flow smoothly through blood vessels. Clumping can occur due to antibodies binding to red blood cells, which may weaken their ability to carry oxygen properly.

How Is the Test Performed?

A small blood sample is drawn from a vein, usually in your arm. The sample is then examined under a microscope to check for clumping patterns.

What Are Possible Results?

Results may be described as negative (no clumping) or positive (evidence of clumping). A positive result may prompt further testing to identify the cause.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: urine

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

RBC Clumping Screen

Frequently asked questions

What causes red blood cell clumping?
Red blood cell clumping can be caused by conditions like autoimmune diseases, infections, or certain medications. It may also occur as part of a broader diagnostic evaluation.
What should I do if my test shows clumping?
If your test shows clumping, your healthcare provider may recommend additional tests or treatments to address the underlying cause. Follow their guidance closely.
Can lifestyle changes help prevent clumping?
While lifestyle changes alone may not prevent clumping, managing conditions like anemia or autoimmune disorders through diet, medication, and regular check-ups can support overall blood health.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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 17, 2026. · Read our editorial policy