The short answer
Hemoglobin is the protein in your red blood cells that carries oxygen. Too little is anemia: under 12.0 g/dL for women and 13.0 for men. Low iron is the most common cause.1
Check your result
Type the number from your report. It stays on this page.
- Severe anemia Under 8.0
- Moderate anemia 8.0 to 10.9
- Below WHO’s cutoff 11.0 to 11.9
- Normal 12.0 to 15.9
- High 16.0 or more
- Severe anemia Under 7.0
- Moderate anemia 7.0 to 9.9
- Mild anemia 10.0 to 10.9
- Normal for pregnancy 11.0 to 15.9
- High 16.0 or more
- Severe anemia Under 7.0
- Moderate anemia 7.0 to 9.4
- Mild anemia 9.5 to 10.4
- Normal for pregnancy 10.5 to 15.9
- High 16.0 or more
- Severe anemia Under 8.0
- Moderate anemia 8.0 to 10.9
- Mild anemia 11.0 to 12.9
- Normal 13.0 to 16.5
- Normal, but high 16.6 to 17.7
- High 17.8 or more
Enter your result to see what it means and what to do next.
Got a result from another lab? Ask Picardo about it. The app explains your results, and a physician can follow up.
Anemia cutoffs and severity grades are WHO’s.1 The top lines are Labcorp’s range and the polycythemia vera criteria.6 The bar isn’t to scale.
Normal hemoglobin
You’re not anemic by WHO’s definition, and you’re below the line where clinicians start to think about too many red cells.1,6
Nothing to worry about.
- 1 Hemoglobin falls only after iron has been low for a while. If you’re tired or have heavy periods, check ferritin anyway: you can be short of iron without being anemic.3
Normal for pregnancy
You’re not anemic by WHO’s cutoffs for pregnancy, which are 11.0 g/dL, or 10.5 in the second trimester.1 Your report may still flag a result under 11.1, the bottom of Labcorp’s range for women.
Nothing to worry about.
- 1 Expect another check later on. US obstetricians recommend screening for anemia at the first prenatal visit and again at 24 to 28 weeks.5
- 2 Iron can run low before hemoglobin does. In pregnancy, US hematologists suggest counting a ferritin of 30 ng/mL or under as iron deficiency.3
Mild anemia your report may not flag
Labcorp’s range for women starts at 11.1, so most results here look normal on your report. But WHO counts anything under 12.0 as anemia, and so does the CDC’s national health survey.1,2 It’s mild, and the cause is worth finding. In younger women, low iron from periods or pregnancy is a common one.4
Not urgent. Worth raising with a clinician in the next few weeks, especially if you’re tired or have heavy periods.
- 1 Check ferritin. US hematologists now suggest counting 30 ng/mL or under as iron deficiency, and up to 50 if you have symptoms of low iron or a risk factor such as heavy periods, a vegan or vegetarian diet or donating blood.3
- 2 If your iron is fine, ask what else could explain it, such as low B12 or folate, or an inherited trait such as thalassemia.1,4
Mild anemia
You have anemia, though only mildly by WHO’s grading.1 Low iron is the most common cause.1 In men, it isn’t something to put down to diet alone. About a third of men with iron-deficiency anemia turn out to have an underlying problem, most often in the gut.4
Not urgent, but find the cause. See a clinician in the next few weeks.
- 1 Check ferritin and iron levels to see whether low iron is the cause.3
- 2 If you’re a man and it is low iron, guidelines recommend checking the gut, usually with a gastroscopy and colonoscopy.4
- 3 If you’re a man and no cause turns up, ask about a testosterone test. Low testosterone goes with lower hemoglobin.7
Moderate anemia: see a clinician soon
Anemia at this level can cause tiredness, dizziness, a racing heart and breathlessness when you exert yourself.1 It needs its cause found and treated. Low iron is the most common one, but not the only one.1,4 In pregnancy, anemia is linked to more cesarean births, and may contribute to smaller or earlier babies.1
See a clinician within a week or so. Go the same day if you’re short of breath at rest, have chest pain or have black or bloody stools.
- 1 Ask for ferritin, iron, B12 and folate tests to find the cause.3,4
- 2 If it’s low iron, treat it and find out why. Men and women past menopause usually need their gut checked.4
- 3 If you’re pregnant, tell your obstetric team now rather than waiting for your next visit.
Severe anemia: get care quickly
This is severe anemia by WHO’s grading.1 Your blood is carrying much less oxygen than it should, which can bring on chest pain or make heart failure worse.1 Some people need a blood transfusion first, then treatment for the cause.4
See a clinician today or tomorrow. Go to an emergency department now if you have chest pain, are short of breath at rest, feel faint or have black or bloody stools.
- 1 Don’t wait for a routine appointment. Call a clinician today.
- 2 Bring your full blood count. Your MCV, the average size of your red cells, helps point to the cause. Small cells suggest low iron or thalassemia.4
- 3 Expect tests for iron, B12 and folate, and checks for bleeding.4
Normal on your report, but above the polycythemia vera line
Labcorp’s range for men goes up to 17.7, so this won’t be flagged. But above 16.5, hemoglobin meets the first criterion for polycythemia vera, a bone marrow condition that makes too many red cells.6 It’s one of several possible reasons. The others include smoking, living at altitude, sleep apnea, lung disease and testosterone.7
Not urgent. Worth a recheck and a conversation with a clinician over the next few months.
- 1 Repeat the CBC in a few weeks to see whether it stays this high.
- 2 If you smoke, take testosterone or snore heavily, mention it. Each can raise hemoglobin.7
- 3 If it stays high with no clear reason, ask about a JAK2 gene test, which is part of diagnosing polycythemia vera.6
Above the lab’s range
Your hemoglobin is above Labcorp’s range. It’s also at or past the line used to diagnose polycythemia vera: over 16.0 for women and over 16.5 for men.6 Other causes include smoking, sleep apnea, lung disease, living at altitude, testosterone and some tumors.7
Not an emergency on its own. See a clinician in the next few weeks. Get emergency care for chest pain, sudden shortness of breath, weakness on one side of your body or a painful, swollen leg.
- 1 Repeat the CBC to confirm it.
- 2 If you take testosterone, tell the clinician who prescribes it.7
- 3 If there’s no clear cause, ask about a JAK2 gene test and an erythropoietin level, the blood tests used to diagnose polycythemia vera.6
What is a normal hemoglobin level?
Labcorp flags results outside 11.1 to 15.9 g/dL for women and 13.0 to 17.7 for men. Two other lines matter. For women, WHO’s anemia cutoff of 12.0 sits above the bottom of Labcorp’s range. For men, the polycythemia vera line of 16.5 sits below the top of it:1,6
Normal hemoglobin
You’re not anemic by WHO’s definition, and you’re below the line where clinicians start to think about too many red cells.1,6
Nothing to worry about.
- 1 Hemoglobin falls only after iron has been low for a while. If you’re tired or have heavy periods, check ferritin anyway: you can be short of iron without being anemic.3
Normal for pregnancy
You’re not anemic by WHO’s cutoffs for pregnancy, which are 11.0 g/dL, or 10.5 in the second trimester.1 Your report may still flag a result under 11.1, the bottom of Labcorp’s range for women.
Nothing to worry about.
Mild anemia your report may not flag
Labcorp’s range for women starts at 11.1, so most results here look normal on your report. But WHO counts anything under 12.0 as anemia, and so does the CDC’s national health survey.1,2 It’s mild, and the cause is worth finding. In younger women, low iron from periods or pregnancy is a common one.4
Not urgent. Worth raising with a clinician in the next few weeks, especially if you’re tired or have heavy periods.
- 1 Check ferritin. US hematologists now suggest counting 30 ng/mL or under as iron deficiency, and up to 50 if you have symptoms of low iron or a risk factor such as heavy periods, a vegan or vegetarian diet or donating blood.3
- 2 If your iron is fine, ask what else could explain it, such as low B12 or folate, or an inherited trait such as thalassemia.1,4
Mild anemia
You have anemia, though only mildly by WHO’s grading.1 Low iron is the most common cause.1 In men, it isn’t something to put down to diet alone. About a third of men with iron-deficiency anemia turn out to have an underlying problem, most often in the gut.4
Not urgent, but find the cause. See a clinician in the next few weeks.
- 1 Check ferritin and iron levels to see whether low iron is the cause.3
- 2 If you’re a man and it is low iron, guidelines recommend checking the gut, usually with a gastroscopy and colonoscopy.4
- 3 If you’re a man and no cause turns up, ask about a testosterone test. Low testosterone goes with lower hemoglobin.7
Moderate anemia: see a clinician soon
Anemia at this level can cause tiredness, dizziness, a racing heart and breathlessness when you exert yourself.1 It needs its cause found and treated. Low iron is the most common one, but not the only one.1,4 In pregnancy, anemia is linked to more cesarean births, and may contribute to smaller or earlier babies.1
See a clinician within a week or so. Go the same day if you’re short of breath at rest, have chest pain or have black or bloody stools.
Severe anemia: get care quickly
This is severe anemia by WHO’s grading.1 Your blood is carrying much less oxygen than it should, which can bring on chest pain or make heart failure worse.1 Some people need a blood transfusion first, then treatment for the cause.4
See a clinician today or tomorrow. Go to an emergency department now if you have chest pain, are short of breath at rest, feel faint or have black or bloody stools.
Normal on your report, but above the polycythemia vera line
Labcorp’s range for men goes up to 17.7, so this won’t be flagged. But above 16.5, hemoglobin meets the first criterion for polycythemia vera, a bone marrow condition that makes too many red cells.6 It’s one of several possible reasons. The others include smoking, living at altitude, sleep apnea, lung disease and testosterone.7
Not urgent. Worth a recheck and a conversation with a clinician over the next few months.
Above the lab’s range
Your hemoglobin is above Labcorp’s range. It’s also at or past the line used to diagnose polycythemia vera: over 16.0 for women and over 16.5 for men.6 Other causes include smoking, sleep apnea, lung disease, living at altitude, testosterone and some tumors.7
Not an emergency on its own. See a clinician in the next few weeks. Get emergency care for chest pain, sudden shortness of breath, weakness on one side of your body or a painful, swollen leg.
What is hemoglobin?
Think of your red blood cells as delivery trucks, and hemoglobin as the space inside them for oxygen. With less hemoglobin, each trip carries less, and your heart has to work harder to keep your body supplied.
Hemoglobin is the iron-containing protein that fills your red blood cells. It picks up oxygen in your lungs and drops it off everywhere else. A low level is called anemia. It can cause tiredness, dizziness, a racing heart and breathlessness when you exert yourself, or no symptoms at all.1
Your body needs iron to make hemoglobin. When iron runs low, ferritin, your iron reserve, falls first. Hemoglobin drops only if the shortage goes on.3
If you also track your blood sugar with HbA1c, anemia can throw that number off. The HbA1c guide explains how.
What hemoglobin level counts as anemia?
Your lab flags results against its own range. WHO defines anemia by its own cutoffs, reviewed in 2024 and set at the level that only 5% of healthy people fall below.1 For women, the two don’t line up:
| Labcorp flags as low | Anemia, by WHO’s definition | |
|---|---|---|
| Women | Under 11.1 g/dL | Under 12.0 g/dL |
| Men | Under 13.0 g/dL | Under 13.0 g/dL |
WHO’s cutoffs are for ages 15 to 65. In pregnancy, its cutoff is 11.0 g/dL, or 10.5 in the second trimester.1
The CDC’s national health survey now uses WHO’s cutoffs. By them, about 1 in 8 women and girls in the US has anemia, and nearly 1 in 3 Black women and girls.2
WHO raises its cutoffs for two things that push hemoglobin up. Smoking adds 0.3 to 0.6 g/dL, depending on how much you smoke. So if you smoke 10 to 19 cigarettes a day, a woman’s cutoff moves from 12.0 to 12.5. Living at altitude adds more: about 1.1 g/dL at 1,500 to 2,000 meters (roughly 4,900 to 6,600 feet).1
The cutoffs are the same whatever your ancestry. Black people have a lower average hemoglobin than white people, by about 1 g/dL in some studies, which inherited traits such as alpha thalassemia may partly explain. But WHO decided in 2024 not to adjust for race, citing too little evidence, and says to look for the cause of any anemia instead.1
What causes low hemoglobin?
Low iron is the most common cause, but there are others:1,4
- Heavy periods and pregnancy, the main reasons younger women run low on iron4
- Bleeding in the gut, from ulcers, polyps or, less often, cancer4
- Absorbing less iron, as with celiac disease, after stomach surgery or weight-loss surgery, or on long-term acid-reducing drugs4
- Donating blood often1
- Low B12 or folate4
- Long-term illness, such as kidney disease, heart failure or rheumatoid arthritis4
- Inherited traits such as thalassemia or sickle cell1
- Low testosterone, in men7
In men and women past menopause, iron-deficiency anemia needs a cause found, and guidelines recommend checking the gut first.4 If your red cells are small but your iron is normal, a test for thalassemia trait can save you an unnecessary scope.4
How to raise hemoglobin
- Iron tablets
If low iron is the cause. Guidelines recommend one tablet a day, or every other day if it upsets your stomach. Keep going for about three months after your hemoglobin is back to normal, to refill your stores.4
- How much it helps
- A lot
- How sure we are
- Very sure
- Iron infusions
For when tablets don’t work or you can’t take them, or with ongoing bleeding or poor absorption.4
- How much it helps
- A lot
- How sure we are
- Very sure
- Treating the cause
Heavy periods, bleeding in the gut or celiac disease will keep draining iron until they’re treated.4
- How much it helps
- A lot
- How sure we are
- Very sure
- Testosterone, for men with low levels
In trials, testosterone raised hemoglobin by about 1.2 g/dL on average, and more anemic men stopped being anemic than on a placebo.7 It can overshoot, so hematocrit needs checking.7
- How much it helps
- Some
- How sure we are
- Fairly sure
- A blood transfusion
For severe anemia with symptoms. It doesn’t replace the iron you’re missing, so iron treatment still follows.4
- How much it helps
- A lot
- How sure we are
- Very sure
How you raise it depends on the cause, so find that first. For iron-rich foods and how to absorb more from tablets, see the ferritin guide.
What causes high hemoglobin?
A high hemoglobin means your blood is carrying more red cells than usual. Causes include:
- Smoking1,7
- Living at altitude1,7
- Sleep apnea and lung disease such as COPD, which lower your oxygen7
- Testosterone treatment7
- SGLT2 inhibitors, drugs for diabetes, heart failure and kidney disease whose names end in -gliflozin. In trials they raised hemoglobin by about 0.6 g/dL on average, and the authors say it’s unclear whether that matters.8
- Polycythemia vera, a bone marrow condition, and some tumors6,7
The hematocrit guide covers high red cell counts, and testosterone, in more depth.
Who should get a hemoglobin test?
Hemoglobin is part of every complete blood count. It’s worth checking if any of these apply to you:
- You’re tired, dizzy or breathless more than usual.1
- You have heavy periods, eat little iron or donate blood often.1,4
- You have celiac disease, inflammatory bowel disease, kidney disease or heart failure, or have had weight-loss surgery.4
- You’re about to start testosterone, or take it. US urologists recommend checking hemoglobin and hematocrit first.7
- You’re pregnant. US obstetricians recommend a check at the first prenatal visit and again at 24 to 28 weeks.5
Not every expert body agrees on pregnancy screening. The US Preventive Services Task Force found too little evidence to weigh the benefits and harms of routine screening for iron deficiency and iron-deficiency anemia in pregnancy.5
How to get a hemoglobin test, and what it costs
It comes from the complete blood count, which costs $3.75 through Picardo.
Complete blood count
The test this number comes from.
- Results in 2 to 3 days, in the app
- Physician follow-up if you want one
- Free Labcorp draw, or $75 at home
- No other fees. HSA and FSA eligible.
It’s also part of the Base Core Annual – Men, Base Core Annual – Women, Heart Health, Brain Health Screening, Pregnancy, Postpartum, Fertility, Thyroid & Autoimmunity and Celiac / GI panels, if you’d rather test more at once.
Already have a result? Ask Picardo about itQuestions people ask
Should I take iron if my hemoglobin is low?
Not until you know low iron is the cause. Anemia has other causes that iron won’t fix, such as low B12 or folate, inherited traits and long-term illness.1,4 A ferritin test tells you whether you’re short of iron.3
Can you have low iron with normal hemoglobin?
Yes. Iron deficiency comes first, and only turns into anemia if it goes on long enough.3 US hematologists now suggest diagnosing it from ferritin whether or not you’re anemic, at 30 ng/mL or under for most adults.3
How fast should hemoglobin rise on iron?
By about four weeks, it should be up by about 2 g/dL, or back in the normal range. If it isn’t, clinicians look for a reason, such as ongoing bleeding or poor absorption, and may switch you to an iron infusion.4
What hemoglobin do you need to donate blood?
In the US, at least 13.0 g/dL for men and 12.5 for women. Some blood centers accept women from 12.0 if they follow extra safeguards the FDA has approved.9
Often checked alongside
Test details
- Labcorp test
- Complete Blood Count (CBC) With Differential, Reflex to Peripheral Smear Review, 005009
- LOINC
- 718-7
- Sample
- Blood
- Fasting
- Not needed
- Typical lab range
- 11.1 to 15.9 g/dL (women); 13.0 to 17.7 g/dL (men)
- Units
- g/dL. For g/L, multiply by 10.
Sources
- 1 World Health Organization. Guideline on haemoglobin cutoffs to define anaemia in individuals and populations. Geneva: WHO; 2024. www.who.int/publications/i/item/9789240088542
- 2 Williams AM, Ansai N, Ahluwalia N, Nguyen DT. Anemia prevalence: United States, August 2021–August 2023. NCHS Data Brief No. 519. Hyattsville (MD): National Center for Health Statistics; 2024. doi.org/10.15620/cdc/168890
- 3 Powers JM, Lim MY, Achebe MO, et al. American Society of Hematology 2026 guidelines for diagnosis of iron deficiency. Blood Adv. 2026;10(21):7353–7374. doi.org/10.1182/bloodadvances.2025015950
- 4 Snook J, Bhala N, Beales ILP, et al. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut. 2021;70(11):2030–2051. doi.org/10.1136/gutjnl-2021-325210
- 5 US Preventive Services Task Force; Nicholson WK, Silverstein M, Wong JB, et al. Screening and supplementation for iron deficiency and iron deficiency anemia during pregnancy: US Preventive Services Task Force recommendation statement. JAMA. 2024;332(11):906–913. doi.org/10.1001/jama.2024.15196
- 6 Arber DA, Orazi A, Hasserjian RP, et al. International Consensus Classification of myeloid neoplasms and acute leukemias: integrating morphologic, clinical, and genomic data. Blood. 2022;140(11):1200–1228. doi.org/10.1182/blood.2022015850
- 7 Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol. 2018;200(2):423–432. doi.org/10.1016/j.juro.2018.03.115
- 8 Yang Y, Yang C, Wang Y, et al. Sodium-glucose cotransporter 2 inhibitor use and levels of hemoglobin, markers of iron metabolism, and erythropoiesis: a systematic review and meta-analysis of randomized clinical trials. JAMA. Published online October 24, 2026. doi.org/10.1001/jama.2026.19921
- 9 US Food and Drug Administration. General donor eligibility requirements. 21 CFR 630.10. Electronic Code of Federal Regulations. Accessed October 28, 2026. www.ecfr.gov/current/title-21/chapter-I/subchapter-F/part-630/subpart-B/section-630.10
Updated 4 Nov 2026.
This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.