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Hematocrit 28.5 %

= 0.29 L/L in SI units

Men: Markedly low Women: Low

Contact your doctor promptly to discuss this result.

Men1520303841505460Women152028344448546028.5
  • Critically low
  • Markedly low
  • Low
  • Borderline low
  • Normal
  • Borderline high
  • High
  • Markedly high
  • High-normal
Your band (men)
Markedly low · 20–30 %
Distance from typical range (men)
12.5 % below 41.0
Your band (women)
Low · 28–34 %
Distance from typical range (women)
7.5 % below 36.0
SI units
28.5 % = 0.29 L/L

What 28.5 % means — men

A hematocrit of 28.5 % is well below the typical adult male range of about 41–50% and points to moderate to severe anemia. This deserves prompt medical follow-up — within days, not weeks.

Your body is running on a significantly reduced supply of oxygen-carrying red blood cells. Many people adapt gradually if the drop happened slowly, so you may feel more tired than truly ill — but the reserve is thin, and exertion, illness, or additional blood loss could tip things quickly. In men, anemia at this level is never considered normal and always warrants a search for the cause, with slow internal blood loss (often from the digestive tract) high on the list to rule out.

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

  • Iron deficiency, often from slow gastrointestinal blood loss (ulcers, polyps, or other lesions)
  • Vitamin B12 or folate deficiency
  • Chronic kidney disease reducing erythropoietin production
  • Anemia of chronic disease or inflammation
  • Hemolytic anemia (accelerated red cell destruction)
  • Bone marrow disorders
  • A recent significant bleed that is partially recovered
  • Medications such as chemotherapy agents or long-term NSAID use causing hidden bleeding

Symptoms that can go with it

  • Persistent fatigue and low stamina
  • Shortness of breath when climbing stairs or walking briskly
  • Pale skin or pale inner eyelids
  • Headaches
  • Rapid heartbeat or palpitations
  • Feeling cold, especially hands and feet
  • Dizziness when standing up
  • Brittle nails or unusual cravings for ice (with iron deficiency)

Sensible next steps

  1. Contact your doctor within the next few days — sooner if you have chest pain, worsening breathlessness, or black/bloody stools, which need immediate care
  2. Expect follow-up tests such as iron studies, vitamin B12 and folate, reticulocyte count, and a stool test for hidden blood
  3. Ease off strenuous exercise until you've been evaluated
  4. Write down any bleeding you've noticed (gums, stools, urine) and all medications and supplements to share at the visit
  5. Ask your doctor what's driving the anemia — in men this level always deserves a cause, not just an iron pill

What 28.5 % means — women

A hematocrit of 28.5 % is below the typical adult female range of about 36–48%, consistent with mild to moderate anemia. Arrange a medical visit in the next week or two.

This is one of the most common abnormal findings on a CBC in women, and iron deficiency related to menstrual blood loss explains a large share of it. It is very treatable, but it still deserves confirmation with iron studies and a conversation about why it happened — and whether anything besides periods (diet, gut absorption problems like celiac disease, or hidden bleeding) is contributing. If you are pregnant, expected ranges are lower and different rules apply, so flag that to your clinician.

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

  • Iron deficiency from menstrual blood loss, especially with heavy periods
  • Low dietary iron intake (common with restrictive or plant-based diets without planning)
  • Pregnancy (blood naturally dilutes; also increased iron demand)
  • Vitamin B12 or folate deficiency
  • Celiac disease or other gut conditions that impair iron absorption
  • Anemia of chronic disease or inflammation
  • Hypothyroidism
  • Recent blood donation or recent illness

Symptoms that can go with it

  • Tiredness and low stamina
  • Mild breathlessness with exertion
  • Paleness
  • Feeling cold easily
  • Difficulty concentrating or 'brain fog'
  • Sometimes no symptoms at all

Sensible next steps

  1. Book an appointment within the next week or two for a repeat CBC and iron studies
  2. Bring notes on your menstrual pattern, diet, supplements, and any digestive symptoms
  3. If you're pregnant or could be, tell your clinician — interpretation and treatment differ
  4. Hold off on self-prescribing iron until testing confirms deficiency; the dose and duration matter, and so does finding the cause

Frequently asked questions

Is 28.5 % a normal hematocrit level?

No. 28.5 % is well below the typical range for either sex (about 41–50% for men, 36–48% for women) and indicates moderate to severe anemia. It's very treatable in most cases, but it needs a prompt medical evaluation to find and fix the cause.

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?

Yes — it's the most common cause of a mildly elevated result. Hematocrit is a percentage, so when dehydration shrinks the liquid (plasma) portion of your blood, the red cell fraction looks bigger even though you don't actually have extra red cells. That's why doctors usually repeat a high result after you've been drinking normally before drawing conclusions.

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?

At 28.5 %, don't try to fix this yourself with diet or over-the-counter iron — anemia this significant needs a diagnosed cause and a medically supervised plan, which can include prescription-strength iron, IV iron, B12 injections, or treatment of an underlying condition. See your doctor within days and let testing drive the treatment.

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

Related values on your lab report

Sources

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