Hematocrit 56.7 %
= 0.57 L/L in SI units
Contact your doctor promptly to discuss this result.
- Critically low
- Markedly low
- Low
- Borderline low
- Normal
- Borderline high
- High
- Markedly high
- High-normal
At a glance
- Your band (men)
- Markedly high · 54–60 %
- Distance from typical range (men)
- 6.7 % above 50.0
- Your band (women)
- Markedly high · 54–60 %
- Distance from typical range (women)
- 12.7 % above 44.0
- SI units
- 56.7 % = 0.57 L/L
What 56.7 % means — men
A hematocrit of 56.7 % is markedly above the typical adult male range of about 41–50%. Blood this concentrated flows less easily and needs prompt medical evaluation — within days, and same-day at the very top of this range.
Hematology (BSH) guidance recommends investigating a hematocrit that stays above about 52% in a man, and above 60% an absolute excess of red cells is assumed regardless of duration or suspected cause. As hematocrit climbs into this territory, blood viscosity (thickness) rises steeply, which strains circulation and increases the risk of blood clots; many labs treat 60% and above as a critical value because of the risk of spontaneous clotting. This page's scale ends at 60%: a result at that ceiling — or one your report shows above it — is in laboratory critical (panic) territory and calls for same-day contact with a clinician or an emergency department, not just an appointment within days. Possible drivers range from severe dehydration to polycythemia vera or chronic low oxygen, and sorting that out requires testing — this is not a result to sit on.
For adult men, the typical hematocrit reference range is about 41% to 50%, per common US references (Cleveland Clinic cites 41–50% for men). Individual labs vary slightly, and the range printed on your own report governs. Above the range, this page's band boundaries follow widely used clinical conventions: about 52% is the level at which hematology guidance recommends investigating a sustained elevation in men, about 54% is where testosterone-therapy guidance advises reassessing treatment, and 60% and above — the very top of this page's scale — is treated by most laboratories as a critical (panic) value.
Common causes
- Polycythemia vera (a bone marrow disorder producing too many red cells)
- Severe chronic lung disease or long-standing low oxygen levels
- Untreated severe sleep apnea
- Testosterone, anabolic steroid, or EPO (erythropoietin) use
- Severe dehydration
- Kidney tumors or cysts producing excess erythropoietin
- Certain congenital heart conditions
- Heavy smoking combined with living at high altitude
Symptoms that can go with it
- Headaches
- Dizziness or a feeling of fullness in the head
- Blurred or double vision
- Red or ruddy face and palms
- Itching, especially after a warm shower or bath
- Burning or tingling in hands and feet
- Fatigue
- Unexplained leg swelling or pain (possible clot — needs immediate care)
Sensible next steps
- Contact your doctor promptly — aim to be seen within days, and treat a result at or near 60% as a same-day call; seek emergency care immediately for stroke-like symptoms, chest pain, sudden shortness of breath, or a painful swollen leg
- Expect a repeat CBC plus tests such as an erythropoietin level, JAK2 mutation testing, and oxygen saturation checks
- Stay well hydrated in the meantime, but don't assume dehydration alone explains a number this high
- Be candid about testosterone, steroid, or EPO use — it changes the workup and the treatment
- Ask your clinician whether referral to a hematologist is appropriate
What 56.7 % means — women
A hematocrit of 56.7 % is far above the typical adult female range of about 36–48%. A value this high makes blood significantly thicker and needs prompt medical evaluation — within days, and same-day at the very top of this range.
For a woman, hematocrit in the mid-50s is a strong, unambiguous signal that something is driving red cell production or severely concentrating the blood — this is well beyond what ordinary dehydration usually produces. Hematology guidance assumes a genuine excess of red cells, not just a concentrated sample, once a woman's hematocrit exceeds about 56%, which covers most of this band. Blood viscosity rises sharply at these levels, raising the risk of clots, and many laboratories treat 60% and above as a critical value. This page's scale ends at 60%: a result at that ceiling — or one your report shows above it — is in laboratory critical (panic) territory and calls for same-day contact with a clinician or an emergency department, not just an appointment within days. Polycythemia vera, chronic low oxygen, and erythropoietin-producing conditions lead the list of causes, and each is identifiable with targeted testing.
For adult women, US references vary more than for men: StatPearls cites about 36% to 48%, while many US labs and references use a lower upper limit of about 44–45% (Cleveland Clinic cites 36–44%). A result in the mid-40s may carry a high flag on your report even though hematology guidance does not recommend investigation below 48%. Your own lab's printed range governs. At the far high end, most laboratories treat 60% and above — the very top of this page's scale — as a critical (panic) value.
Common causes
- Polycythemia vera
- Severe chronic lung disease or long-standing low oxygen
- Untreated severe sleep apnea
- Severe dehydration or major fluid loss
- EPO (erythropoietin) or testosterone/anabolic steroid use
- Kidney tumors or cysts producing excess erythropoietin
- Certain congenital heart conditions
- Rare inherited red cell disorders
Symptoms that can go with it
- Persistent headaches
- Dizziness or ringing in the ears
- Blurred or disturbed vision
- Reddish or ruddy skin, especially face and palms
- Itching after warm showers or baths
- Burning pain or tingling in hands and feet
- Fatigue
- Leg swelling or pain (possible clot — seek immediate care)
Sensible next steps
- Contact your doctor promptly — within days, and treat a result at or near 60% as a same-day call; seek emergency care immediately for stroke-like symptoms, chest pain, sudden breathlessness, or a swollen painful leg
- Expect a repeat CBC, erythropoietin level, JAK2 mutation testing, and oxygen checks
- Stay hydrated, but treat that as a stopgap, not an explanation, at this level
- Mention any hormone therapy or performance supplements — it directly shapes the workup
- Ask whether a hematology referral is the right next step
Frequently asked questions
Is 56.7 % a normal hematocrit level?
No. 56.7 % is markedly above the typical range for either sex (about 41–50% for men, 36–48% for women). Blood this concentrated flows poorly and raises clot risk, so contact your doctor promptly — this result should be evaluated within days, and a result at or near 60% warrants same-day contact.
What hematocrit level is considered dangerously low?
Most US laboratories flag a hematocrit below roughly 20–21% as a critical (panic) value, because at that point the blood carries so little oxygen that the heart is under serious strain. That corresponds approximately to a hemoglobin under 7 g/dL, the threshold at which blood transfusion is often considered. Danger also depends on speed: a rapid drop from bleeding is more dangerous than the same number reached slowly. Any result near that zone warrants urgent contact with a doctor.
Can dehydration make my hematocrit high?
Dehydration raises hematocrit, but it rarely explains a value as high as 56.7 % by itself — that usually takes severe fluid loss you'd definitely notice. A result at this level should be treated as real until proven otherwise, so see your doctor promptly rather than just drinking water and hoping it resolves.
What's the difference between hematocrit and hemoglobin?
They measure related but different things. Hemoglobin measures the oxygen-carrying protein inside red blood cells, in grams per deciliter; hematocrit measures how much of your blood's volume the red cells occupy, as a percentage. They usually move together — a rough rule of thumb is hematocrit ≈ 3 × hemoglobin — and doctors typically read them side by side on the CBC. When they diverge, the other red cell measurements (like MCV and MCHC) help explain why.
How can I raise a low hematocrit?
It depends entirely on the cause, which is why testing comes first. Iron helps only if you're iron deficient; B12 or folate help only for those deficiencies; kidney-related anemia and chronic-disease anemia need different approaches altogether. Taking iron without a confirmed deficiency can cause side effects and hide the real problem. Get iron studies and a diagnosis, then follow a plan your clinician sets — and recheck the CBC afterward to confirm it worked.
Why are hematocrit ranges different for men and women?
Two main reasons. Testosterone stimulates red blood cell production, so men naturally run higher — typically about 41–50%, versus about 36–48% for women. Menstrual blood loss also gradually lowers iron stores and red cell mass in many women during reproductive years. This is why the same number can be read differently by sex: 40% is slightly low for a man but comfortably normal for a woman. After menopause, women's values often drift up toward the male range.
Check a different Hematocrit value
Sources
- Hematocrit Test — MedlinePlus (National Library of Medicine)
- Hematocrit test — Mayo Clinic
- Hematocrit (StatPearls) — NCBI Bookshelf / StatPearls
- Hemoglobin and Hematocrit (Clinical Methods, 3rd edition) — NCBI Bookshelf
- Hematocrit — Cleveland Clinic
Educational information, not medical advice. Reference ranges vary between labs — always compare with the range printed on your own report and discuss results with your doctor. Full disclaimer