When hemoglobin counts as low
Hemoglobin is the oxygen-carrying protein in red blood cells, and a value below your lab’s range for men means anemia. MedlinePlus gives a typical adult male range of 13.8 to 17.2 g/dL, and ranges vary slightly between labs.
Symptoms depend on how low and how fast. NHLBI lists tiredness, weakness, shortness of breath, dizziness, headaches and an irregular heartbeat. Many men with mild anemia notice only that hills and stairs feel harder than they used to.
Why anemia in a man always needs a cause
Adult men do not have a built-in monthly blood loss, so anemia in a man points to something specific. NHLBI notes that anemia can be a sign of a more serious condition, such as bleeding in the stomach, inflammation from an infection, kidney disease, cancer or autoimmune disease.
That is why the answer is never just an iron pill or a vitamin. Treating the number can make it look better on the next report while the cause, sometimes a slow bleed from the bowel, carries on unnoticed.
Start with red cell size
The MCV on your blood count, the average red cell size, splits anemia into three groups and points to the next tests. The groupings below follow MedlinePlus’s guide to red cell indices, with low testosterone added from the Endocrine Society guideline.
| Red cell size | Common causes in men | Next labs |
|---|---|---|
| Small (low MCV) | Iron deficiency from blood loss; an inherited trait such as thalassemia | Ferritin, iron and transferrin saturation |
| Normal MCV | Kidney disease, long-term illness or inflammation, sudden blood loss, low testosterone | Creatinine and eGFR, CRP, morning testosterone, reticulocyte count |
| Large (high MCV) | Low vitamin B12 or folate, liver disease, some medicines | B12, folate, liver tests |
Our CBC blood test guide walks through the other red cell lines, such as RDW, that help refine this sorting.
The follow-up labs that separate the causes
A short list of follow-up tests usually names the cause.
- Ferritin and transferrin saturation show whether iron stores are empty. A low ferritin in a man starts a search for bleeding; see our ferritin blood test page.
- Vitamin B12 and folate explain most large-cell anemias. Our pages on the vitamin B12 test and the folate test cover each.
- Reticulocyte count shows whether the marrow is responding. MedlinePlus explains that a low count fits iron, B12 or folate deficiency, marrow failure or kidney disease, while a high count fits bleeding or red cells being destroyed.
- Creatinine and eGFR check the kidneys, which make erythropoietin, the hormone that drives red cell production; see our eGFR and creatinine page.
- Morning testosterone when the anemia is mild, normal-sized and otherwise unexplained.
When iron deficiency is confirmed, the AGA guideline recommends both an upper endoscopy and a colonoscopy for men, even without digestive symptoms, and uses a ferritin cutoff of 45 ng/mL in people with anemia.
Where low testosterone fits
Low testosterone is a real but usually mild cause, and it is considered only after the others. The Endocrine Society guideline lists mild, unexplained anemia with normal-sized cells among the findings that can prompt a testosterone check.
The guideline also reports that in older men with low testosterone and anemia, a greater share of those treated with testosterone saw hemoglobin rise by more than 1 g/dL than those given placebo. That benefit only counts when a bleed or deficiency has been ruled out; our page on low testosterone symptoms covers the other signs to look for.
Signs that need emergency care
Some anemia is an emergency. Call 911 or go to an emergency room for black or tarry stools, vomiting blood, fainting, chest pain, or severe shortness of breath at rest. These suggest active bleeding or a heart under strain and should not wait for repeat labs.
How Ultimate Male works up low hemoglobin
Hemoglobin is part of the complete blood count in our TRT pre-screening panel, and iron and B12 are in our targeted preventative panel, all drawn on site at San Gabriel or Downey with results in about 24 to 48 hours. When hemoglobin is low, your provider reads it with the MCV and orders the follow-up labs that fit the pattern.
If the picture suggests bleeding, you are guided toward a gastrointestinal evaluation before anything else, and testosterone is discussed only once other causes have been excluded. See all of our testing options at preventative blood testing.
