Hemoglobin S Percentage in Blood (Gastrografin-Enhanced Study)
This test measures the proportion of hemoglobin S (the abnormal form of hemoglobin linked to sickle cell trait or disease) in your blood, often performed after a contrast study using Gastrografin (a radiopaque dye).
["Assessing your blood’s hemoglobin S levels can help diagnose or monitor sickle cell trait/disease or evaluate gastrointestinal issues after contrast imaging."]
Key facts at a glance
- LOINC
- 14563-1
- Short code
- Hgb sp1 Stl gastro Ql
- Synonyms
- Hgb sp1 Stl gastro Ql
- Category
- hematology
- Sample
- stool
- Container
- Clean container
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms of sickle cell trait (e.g., mild pain, fatigue) or if Gastrografin was used for imaging (e.g., CT scans of the abdomen or pelvis). It helps determine if the dye caused any changes in your red blood cells, including potential sickling.
What to Expect Before the Test
No special preparation is needed unless instructed by your doctor. If Gastrografin was used, you may have had a prior imaging study. Blood will be drawn from a vein, usually in your arm, and may cause a brief pinch or discomfort.
What the Test Results Mean
The percentage of hemoglobin S in your blood is compared to standard ranges for healthy individuals. Higher-than-normal levels may indicate sickle cell trait or disease, while abnormal findings after contrast exposure could signal complications like hemolysis (destruction of red blood cells).
Common Causes of Abnormal Results
Abnormal hemoglobin S percentages can result from genetic predisposition (sickle cell trait/disease), exposure to Gastrografin (which may cause red blood cell changes), or other underlying conditions affecting red blood cell health.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated hemoglobin S percentages are critical for diagnosing sickle cell trait (a genetic condition that may affect blood flow) or disease (which can cause severe pain, organ damage, or infections). After contrast imaging, abnormal results may prompt further evaluation for complications like hemolysis or kidney issues. This test helps guide treatment or monitoring plans.
Short name
Hemoglobin S % (Gastrografin)
Frequently asked questions
What does a positive result mean?
Will I need follow-up tests if my results are abnormal?
Is this test painful?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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