Do You Have Low Hemoglobin? Signs, Normal Levels, And What To Do

Hemoglobin is a fundamental protein present in red blood cells, whose function is to transport oxygen from the lungs to the tissues, and return carbon dioxide for elimination. 

However, in a blood test, abnormal hemoglobin levels can alert to conditions such as anemia, especially when they are below the appropriate limits.

Optimal hemoglobin levels depend on age and sex. According to Dr. Besses, a normal level of 13 g/dL or higher is considered normal for adult men, while for women it should be 12 g/dL or higher. 

In children under six years of age, the threshold is set at 11 g/dL. On the other hand, excessive hemoglobin is defined as levels above 16.5 g/dL in men and 16 g/dL in women.

Low hemoglobin symptoms: warning signs to watch out for

Symptoms caused by low hemoglobin levels can vary depending on the speed and degree of the decline. A rapid loss, such as that caused by acute hemorrhage, may manifest with extreme weakness, rapid heart rate, dizziness, paleness, or intense fatigue. 

In contrast, a progressive and chronic decrease, as occurs in cases of silent internal bleeding, can go almost unnoticed and not significantly affect daily activities.

What does low hemoglobin mean? Diagnosing anemia

A hemoglobin level below the reference values ​​is clinically associated with anemia. Dr. Besses clarifies that hematologists do not base their definition on the number of red blood cells, but rather on the concentration of hemoglobin in the blood. Iron deficiency anemia—caused by a lack of iron—is the most common form, especially in women of childbearing age, due to heavy menstruation or pregnancy.

Iron deficiency is the main cause of low hemoglobin levels, although other underlying conditions can also cause it. It is important to distinguish between iron deficiency (low iron stores without anemia) and iron deficiency anemia itself. In men or postmenopausal women, these alterations may be linked to blood loss from the digestive tract, justifying the need for endoscopic studies such as colonoscopies or gastroscopies.

Common symptoms of iron deficiency anemia

The most common symptoms include unexplained fatigue, weakness, decreased physical performance, hair loss, headaches, dyspnea (shortness of breath), and restless legs syndrome. These clinical signs can affect quality of life and are often present even when hemoglobin levels are not extremely low.

If low hemoglobin levels are suspected, diagnosis should be guided by a complete medical history and a detailed complete blood count. Hematologists examine not only hemoglobin, but also other parameters such as the size of red blood cells, leukocytes, and platelets. It is never recommended to begin treatment without identifying the specific cause of the anemia, which may require additional testing, ranging from ferritin analysis to endoscopic examinations or bone marrow biopsies.