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Hemoglobin (Hb) with Percent Paroxysmal Nocturnal Hemoglobinuria (PNH) Marker

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

This test measures your red blood cells’ hemoglobin level and checks for a rare condition called Paroxysmal Nocturnal Hemoglobinuria (PNH), which can cause abnormal blood breakdown and other complications.

Quick summary

["Your blood hemoglobin and PNH status may be checked if you have unexplained anemia, blood disorders, or symptoms like fatigue or bruising."]

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

Key facts at a glance

LOINC
69950-4
Short code
Hgb Pcar-mCnc
Synonyms
Hgb Pcar-mCnc
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
12
Ref high
17.5
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85018
SNOMED
900000000000003004
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test if you have symptoms like unusual fatigue, easy bruising, or blood in urine/stool. It’s also used to monitor PNH in patients already diagnosed with the condition.

What to Expect Before the Test

No special preparation is needed. A blood sample is drawn from a vein, usually in your arm, by a healthcare professional.

What the Results Mean

Hemoglobin levels help assess anemia, while PNH screening detects abnormal red blood cell markers. Results may guide treatment for blood disorders or PNH.

Common Conditions This Test Helps Diagnose

This test helps diagnose PNH, a rare blood disorder causing red blood cells to break down abnormally, or confirms anemia due to other causes.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Hb with PNH Screening

Frequently asked questions

What does a low hemoglobin level mean?
A low hemoglobin level suggests anemia, which could be due to many causes, including PNH. Your doctor will discuss symptoms and other test results to determine the exact reason.
How is PNH detected in this test?
PNH is detected by checking for specific markers in your red blood cells that are absent in healthy blood. This helps identify the rare condition that can cause blood breakdown.
Can this test be done at home?
No, this test requires a blood sample collected by a healthcare professional in a lab setting.
  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 16, 2026. · Read our editorial policy