Hemoglobin

What is Hemoglobin?

Hemoglobin is the protein in red blood cells that carries oxygen from your lungs to tissues throughout your body, then transports carbon dioxide back to your lungs for exhalation.

Each hemoglobin molecule contains iron, which binds to oxygen. This is why iron deficiency causes anemia — without enough iron, your body can't produce enough functional hemoglobin.

Hemoglobin levels are measured in a complete blood count (CBC) and are the primary indicator of anemia.

Normal Ranges

Group	Hemoglobin Level
Adult men	13.5–17.5 g/dL
Adult women	12.0–15.5 g/dL
Pregnant women	11.0–14.0 g/dL

Normal ranges can vary by altitude (higher elevation increases hemoglobin) and individual factors.

Why It Matters

Oxygen Delivery

Hemoglobin determines how much oxygen your blood can carry. Low hemoglobin means less oxygen reaches your tissues, causing fatigue, weakness, and shortness of breath.

Anemia Detection

Anemia is defined as hemoglobin below normal range. It has many causes, including:

Iron deficiency
Vitamin B12 or folate deficiency
Chronic disease
Blood loss
Bone marrow problems

Performance and Energy

Optimal hemoglobin levels are crucial for physical performance, mental clarity, and overall energy. Even mild anemia can significantly impact quality of life.

Low Hemoglobin (Anemia)

Symptoms

Fatigue and weakness
Pale skin
Shortness of breath
Dizziness
Cold hands and feet
Rapid heartbeat

Common Causes

Iron deficiency — The most common cause worldwide
Heavy menstrual periods — Major cause in premenopausal women
Vitamin B12 deficiency — Causes megaloblastic anemia
Chronic disease — Cancer, kidney disease, autoimmune conditions
Blood loss — Gastrointestinal bleeding, surgery

High Hemoglobin

High hemoglobin is less common but can indicate:

Dehydration — Concentrates blood
Living at high altitude — Body compensates for lower oxygen
Smoking — Reduces oxygen delivery, body makes more hemoglobin
Lung disease — Chronic hypoxia triggers production
Polycythemia vera — Rare bone marrow disorder

Hemoglobin vs. Hematocrit

These markers are closely related:

Hemoglobin measures the amount of oxygen-carrying protein
Hematocrit measures the percentage of blood volume made up of red blood cells

Both reflect anemia or polycythemia, and they usually move together.

How to Improve Low Hemoglobin

Depends on the cause:

For iron deficiency:

Iron-rich foods (red meat, liver, beans, spinach)
Iron supplements (take with vitamin C)
Treat underlying blood loss

For B12 deficiency:

B12 supplements or injections
Animal products in diet

For chronic disease:

Treat the underlying condition

How Often to Test

Routine checkups: CBC typically included every 1–2 years
Women with heavy periods: Annually
Pregnancy: Multiple times during prenatal care
Chronic conditions: As directed