Histidine concentration in hair (24-hour integrated)
This test measures the amount of histidine, an essential amino acid, collected from your hair over a 24-hour period. It may be used to assess metabolic or genetic conditions affecting amino acid metabolism.
["This test helps evaluate how your body processes certain amino acids, potentially identifying underlying metabolic or genetic disorders."]
Key facts at a glance
- LOINC
- 47644-0
- Short code
- Histidine SFr Hair
- Synonyms
- Histidine SFr Hair
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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 Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms or a family history suggestive of metabolic disorders, such as amino acidurias (conditions where amino acids are not properly processed in the body). It could also be part of a broader evaluation for genetic testing or research studies focused on amino acid metabolism.
What to Expect Before the Test
No special preparation is typically required for this test. Hair samples are usually collected by a healthcare professional. You may be asked to avoid certain medications or dietary supplements that could interfere with results, but this depends on your specific situation.
What the Test Involves
A small amount of hair is collected, usually from the scalp or other areas. The sample is then analyzed to measure the integrated 24-hour levels of histidine. This test is often non-invasive and painless.
How Results Are Interpreted
Results are compared to reference ranges for histidine in hair, though specific ranges can vary by lab. Elevated levels might suggest certain metabolic or genetic conditions, while lower levels could indicate other metabolic issues or deficiencies.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Histidine is a non-essential amino acid, but its levels in hair can provide insights into overall amino acid metabolism. Abnormalities in histidine or related amino acids may indicate inherited metabolic disorders, such as histidinemia or other aminoacidopathies. Early detection can guide treatment and management strategies.
Short name
Histidine in Hair (24h)
Frequently asked questions
What does a high or low histidine level in hair mean?
Is there any risk or discomfort with this test?
How long will it take to get my results?
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