CBC Results Explained: Low Hemoglobin and What It Means

You have opened your blood test results and hemoglobin is flagged, with no explanation beyond the number. It is one of the most common reasons people bring us their lab reports: the lab is Spanish, the comments are in Spanish, and nothing tells you whether to worry. Most of the time there is a simple explanation, but it helps to know what each value measures so you neither over-worry nor miss what matters.

The complete blood count (CBC, hemograma in Spanish) counts and describes your blood cells. It does not diagnose a disease on its own; it points to what should be looked at next.

• Hemoglobin: the protein in red cells that carries oxygen. Below your laboratory's range it is called anaemia, which is a finding, not a disease in itself.
• Hematocrit: the percentage of blood made up of red cells; it usually moves with hemoglobin.
• MCV and MCH: the size and hemoglobin content of each red cell. They help point to the cause, for example low iron, or low vitamin B12 or folate.
• White cells (leukocytes): often rise during an infection.
• Platelets: involved in clotting.

Common causes of low hemoglobin: iron deficiency, low vitamin B12 or folate, blood loss (for example heavy periods), chronic illness and some medicines. Always use the reference range printed on your own report, because it varies between laboratories.

When to seek advice: if the value is low on two separate tests, if you feel unusually tired, pale, dizzy or have palpitations, or if you take blood thinners. Call 112 or go to an emergency department if you have chest pain, marked breathlessness, fainting, black stools or heavy bleeding.

If your results come from a Spanish laboratory, an online consultation lets us go through them with you calmly, in your language, and decide whether more investigation is needed, where clinically appropriate following a genuine evaluation. You can book a video consultation or read our guide to blood tests and lab work in Spain. This service is for urgent, non-emergency care; in an emergency, call 112.