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Hemoglobin (Hb) and Hematocrit (Hct) Profile from Whole Blood

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

This test measures your blood’s hemoglobin (the protein that carries oxygen) and hematocrit (the percentage of red blood cells in your blood). These levels help assess your red blood cell health and overall blood health.

Quick summary

["Hemoglobin and hematocrit levels help diagnose and monitor conditions like anemia or blood disorders."]

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

Key facts at a glance

LOINC
40547-2
Short code
Hgb H Bld Ql
Synonyms
Hgb H Bld Ql
Category
hematology
Sample
whole-blood
Container
Lavender-top (EDTA)
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
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is Measured?

Your blood sample is analyzed to determine two key values: hemoglobin concentration and hematocrit percentage. Hemoglobin is measured in grams per deciliter (g/dL), while hematocrit is expressed as a percentage.

Why Is This Test Done?

Doctors may order this test to check for anemia (low red blood cells), polycythemia (high red blood cells), or other blood-related conditions. It’s often part of routine check-ups, evaluations for fatigue, or symptoms like pale skin, dizziness, or shortness of breath.

Sample Collection and Preparation

A small blood sample is drawn from a vein, usually in your arm. The sample is sent to the lab for analysis. No special preparation is needed, but fasting may be required depending on additional tests included in your profile.

What to Expect Before the Test

You may feel slight discomfort during the blood draw, but it typically lasts only a few minutes. If you’re nervous, let your healthcare provider know—they can take steps to make the process more comfortable.

Reference range

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

Specimen: whole-blood

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/Hct Profile

Frequently asked questions

How long does it take to get my results?
Results are usually available within 1–3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the results with you during your follow-up visit.
Can I eat or drink before this test?
No special diet is required for this test alone, but if your doctor has included other tests (like glucose or lipid panels), follow their instructions. Generally, you can eat and drink normally unless advised otherwise.
What are normal ranges for hemoglobin and hematocrit?
Normal ranges vary by age, sex, and overall health. For adults, typical hemoglobin levels range from about 12–16 g/dL for women and 13–18 g/dL for men, while hematocrit levels are roughly 35–45% for women and 40–52% for men. Your doctor will interpret these values in relation to your specific health status.
  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