Hemoglobin

Researched

Hemoglobin (Hgb/Hb)

Blood Cells • Last tested 2026-01-28

What It Measures

This test measures the concentration of hemoglobin protein in your blood, reported in grams per deciliter (g/dL). It reflects your body's ability to carry oxygen to cells and tissues, which is essential for energy production, organ function, and exercise capacity.

Hemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to tissues and returning carbon dioxide for exhalation. It is a fundamental marker of oxygen-carrying capacity and overall blood health, making it one of the most commonly ordered lab tests in medicine.

Current Value

15.6g/dL
Reference Range: 13.517.5 g/dL(standard)
Optimal Range: 13.515.5 g/dL(Functional/optimal range based on Peter Attia and functional medicine consensus. Standard lab ranges: Males 13.5–17.5 g/dL, Females 12.0–15.5 g/dL. Functional optimal: Males 14.0–15.5 g/dL, Females 13.0–14.5 g/dL. The min/max fields reflect a combined midpoint; see male/female specifics in this note.)
In Range
-1.2 (-7.1%) from previous test
13.5 g/dLOptimal: 13.515.517.5 g/dL

What High Means

Elevated hemoglobin (polycythemia) can indicate dehydration, chronic hypoxia (from lung disease, sleep apnea, or high altitude living), polycythemia vera (a bone marrow disorder), smoking, testosterone use or abuse, congenital heart disease, or kidney tumors producing excess erythropoietin. High hemoglobin increases blood viscosity, raising the risk of blood clots, stroke, and heart attack.

Possible Symptoms

Headaches, dizziness, blurred vision, flushing or ruddy complexion, itching (especially after warm showers), enlarged spleen, fatigue, joint pain, excessive sweating, increased blood clot risk

What Low Means

Low hemoglobin (anemia) can result from iron deficiency (most common cause worldwide), vitamin B12 or folate deficiency, chronic kidney disease (reduced erythropoietin production), chronic inflammation, bone marrow disorders, blood loss (menstruation, GI bleeding), hemolytic anemias, thalassemia, or chronic diseases. Low hemoglobin impairs oxygen delivery, causing fatigue, weakness, and reduced exercise tolerance.

Possible Symptoms

Fatigue, weakness, pale skin, shortness of breath, dizziness or lightheadedness, cold hands and feet, brittle nails, headaches, rapid or irregular heartbeat, chest pain, poor exercise tolerance, pica (craving non-food items like ice)

Risk Factors

Iron deficiency anemia, vitamin B12 deficiency, folate deficiency, chronic kidney disease, thalassemia, sickle cell disease, polycythemia vera, chronic obstructive pulmonary disease (COPD), sleep apnea, heart failure, gastrointestinal bleeding, heavy menstruation, bone marrow failure, lead poisoning, chronic inflammation

Actionable Advice

Supplements

  • Iron bisglycinate
  • Vitamin C (enhances iron absorption)
  • Vitamin B12 (methylcobalamin)
  • Folate (5-MTHF)
  • Copper
  • Vitamin B6
  • Vitamin A
  • Chlorophyll
  • Spirulina
  • Beetroot extract

Diet & Lifestyle

  • Eat iron-rich foods: red meat, organ meats, dark leafy greens, legumes, and fortified cereals
  • Pair iron-rich foods with vitamin C sources to enhance absorption
  • Avoid drinking coffee or tea with meals (tannins inhibit iron absorption)
  • Address underlying causes of blood loss (e.g., heavy periods, GI issues)
  • Engage in regular moderate exercise to stimulate red blood cell production
  • Ensure adequate sleep and treat sleep apnea if present
  • Avoid smoking, which artificially elevates hemoglobin
  • Stay well-hydrated to avoid falsely elevated readings
  • Cook in cast iron cookware to increase dietary iron intake
  • Get tested for celiac disease or H. pylori if iron deficiency is persistent despite supplementation

Ask AI

Ask questions about your Hemoglobin results, trends, and what you can do to optimize.

Historical Trend

Reference
Optimal
Last researched Feb 14, 2026

All Readings

DateValueChange
2026-01-2815.6 g/dL-1.2
2025-09-1816.8 g/dL+0.1
2025-08-2516.7 g/dL+0.5
2025-07-3116.2 g/dL+1.6
2025-06-2714.6 g/dL