Low Hemoglobin: Causes and What It Means

You opened your test report and saw hemoglobin below normal. The number on the report is not a diagnosis. The next step is to understand where the deficiency comes from and what it means for you.

What hemoglobin is and what level is considered low

Hemoglobin is an iron-rich protein. It gives blood its red color and carries oxygen from the lungs to the rest of the body.

When hemoglobin and red blood cells are low, oxygen transport drops. Tissues are starved — this condition is called anemia.

Hemoglobin norms depend on sex and age. So compare your number with the reference values on your laboratory's report.

A complete blood count also looks at other indicators. The color index is normally 0.86–1.1, reticulocytes — 0.5–2%.

Low hemoglobin does not only occur with iron deficiency. There are B12- and folate-deficiency, hemolytic, and aplastic anemias.

Anemia affects about a third of the world's population. Its most common type is iron-deficiency anemia.

Why hemoglobin drops

There are three mechanisms: blood loss, insufficient production of red blood cells, and their accelerated destruction. Most often the cause is a lack of iron.

• Heavy menstruation and pregnancy.
• Bleeding in the stomach and intestines: NSAIDs (ibuprofen, aspirin), ulcers, inflammation of the intestines or esophagus, hemorrhoids, less commonly stomach or intestinal cancer.
• A diet deficient in iron, folic acid, or vitamin B12.
• Hereditary blood disorders, aplastic anemia, G6PD deficiency.
• Chronic inflammation, infections, tumors.

If the cause is unclear, the doctor orders additional tests.

Low hemoglobin in women

Women face anemia more often than men. Heavy periods are one of the most common causes of iron loss.

The second common situation is pregnancy. Plus, anemia is more common in children and older adults.

Hemoglobin during pregnancy

During pregnancy, iron-deficiency anemia is usually caused by a lack of iron in the diet.

There is a nuance: pregnant women can have hydremia. The volume of the liquid part of the blood increases, and hemoglobin on the report looks below normal. This is not the same as true anemia.

In any trimester of pregnancy, low hemoglobin is discussed with a doctor: untreated anemia increases the risk of complications before and after childbirth. The doctor evaluates the complete blood count and ferritin.

Hemoglobin in cancer

Anemia can accompany oncological diseases. Tumors of the stomach and intestines are one of the less common causes of bleeding: intestinal or stomach cancer occurs less often than other causes. Neoplastic diseases of the bone marrow and extramedullary tumors are classified as normochromic anemias.

An oncological cause is determined by a doctor. That is why one test is not enough — additional examinations are needed.

Symptoms, risks, and when to see a doctor

Classic signs: fatigue and lack of energy, shortness of breath, noticeable heartbeat, pale skin, headache. A person may feel cold, be dizzy, and become irritable.

Less often, ringing in the ears, a strange taste of food, itching, a sore tongue, and hair loss are bothersome. There may be a craving for non-food items — paper, ice, difficulty swallowing, cracks in the corners of the mouth, spoon-shaped nails, restless legs.

Often anemia does not manifest in any way and is found incidentally in a test. To check, a complete blood count is done. If the cause is unclear — serum ferritin, a fecal occult blood test, a referral to a specialist.

Without treatment, iron-deficiency anemia increases the risk of infections. Complications from the heart and lungs are possible — tachycardia, heart failure.

A low hemoglobin number by itself is not a reason to call an ambulance. 103 or 112 — if signs of a heart attack or stroke appear against the background of anemia, or the condition deteriorates rapidly.

With low hemoglobin, go to a general practitioner: they will take a history and decide which examinations are needed. This material is for reference and does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer