Symptoms and Signs of Anemia

Anemia is the name given to reduced number of red blood cells. Red blood cells, also called RBCs or erythrocytes, are the cells responsible for transporting oxygen through the bloodstream. In this paper we explain the main symptoms of anemia.

To understand the symptoms of anemia it is necessary to understand the work of the red blood cells (RBCs).

The blood is not a purely liquid substance, there are millions of diluted cells, red blood cells being the most abundant. The red cell is a cell whose main function is to transport oxygen through the blood to the tissues. Within the red blood cells there is a protein called hemoglobin, which is the structure responsible for binding to the oxygen molecule. The oxygen enters the red blood cells and binds to hemoglobin, thus it may be carrying throughout the body.


Consider some facts

When we breathe, our lungs are filled with oxygen. As the blood passes through the lung it is rich in red blood cells (whole blood has somewhere around 5 million red blood cells), the inhaled oxygen is easily absorbed by them, remaining bound to hemoglobin. The oxygenated blood leaves the lungs and returns to the heart, where it is pumped to the rest of the body. The oxygen-rich blood is bright red, as this is the color that takes over when the hemoglobin is bound to oxygen. As the blood is coming to the organs and tissues of the body, oxygen in red blood cells is progressively delivered to the cells that need it for energy. The oxygen-poor blood cells go back to the lungs to receive an additional oxygen supply, restarting the cycle.

After this brief explanation, we can talk specifically about the symptoms of anemia.

Signs and symptoms of anemia

Tiredness and lack of energy

When the quantity of cells that carry oxygen is reduced, the body's ability to deliver oxygen to all tissues becomes compromised. As oxygen is essential for cells to function, its reduction causes symptoms such as tiredness, weakness, dizziness, lack of courage, lack of concentration, drowsiness and headache.

Young and healthy people can better tolerate the fatigue of anemia, feeling these symptoms only when they need to make efforts. And older people tend to complain a lot about tiredness and lack of energy, performing simple tasks such as dressing, bathing and walking through the house present difficulties for them. Fatigue is the most common and typical symptom of anemia.

Shortness of breath

Shortness of breath usually occurs in severe cases of anemia, or in patients who already have some degree of cardiac and / or lung malfunction. As the amount of oxygen reaching the cells is insufficient, the body's response is to accelerate the respiratory rate in an attempt to increase blood oxygenation.

Patients with anemia may complain of shortness of breath and present a faster breathing.


Tachycardia - heart racing

Just as there is an increased respiratory rate, there is also an increased activity of the heart. The heart speeds up trying to increase the amount of blood reaching the tissues. The logic is simple, if the blood is low in oxygen, we need to get more blood to the cells to receive an acceptable amount of oxygen.

Tachycardia also triggers the onset of heart murmur.

Chest pain

Chest pain in patients with heart disease this reduction in tissue oxygenation and rapid heartbeat cannot be tolerated. If the patient already has a diseased heart, which normally works already at its limit, anemia, even mild, can be the final straw needed to trigger a cardiac ischemia.


The pallor of the skin and mucous membranes occurs for two reasons. The main one is reduction of blood circulation in peripheral tissues (such as skin) since the organism is to give priority to important organs of the body, deflecting the flow of blood to them. As the skin receives less blood, it becomes paler. Furthermore, as there is a fall in the number of circulating erythrocytes, blood becomes more dilute, assuming a less vivid color. Therefore, in anemia, skin and mucous membranes are receiving less blood, and the blood is diluted because there comes a lack of red blood cells. Besides pallor, the skin can also become colder.

In people with darker skin the pale skin is harder to be noticed. To identify anemia, one must look to color of the mouth and conjunctiva of the eyes, which are shown in fainter anemia.

The pallor may not be noticed until the hemoglobin falls to values around 10g/dl. Therefore, only the absence of pallor does not rule out anemia.


The cramps occur for the same reasons as fatigue and paleness. The lack of oxygenation of the muscles combined with reduced effective blood circulation, cause disturbances in the normal functioning of the muscles, which may arouse involuntary contractions.


Hypotension is a common symptom in anemia that arises because of blood loss. When the patient has bleeding, they lose not only erythrocytes but also blood volume, which leads to a drop in blood pressure.

Hypotension clinically manifests as extreme weakness, difficulty standing, dizziness and feeling faint.

Acute and chronic anemia

The intensity of the symptoms of anemia depends on two factors: the time of onset of anemia and the severity of it. Chronic anemia, that settles slowly and gradually, over several weeks or months, does not usually cause symptoms until well advanced stages. Because the process is slow, the existing hemoglobin has time to adapt, becoming more effective in capturing and distributing oxygen throughout the body.

Normal hemoglobin values are greater than 13 g/dl for men and for women greater than 12 g/dl. Due to the adaptability of red blood cells, patients with chronic anemia can remain asymptomatic at rest until 8 or 9 g/dl levels of hemoglobin. Logically health status is evaluated by a prior account. If the patient already has other diseases, mainly from heart or lungs, their ability to adapt to anemia is much reduced. Young patients in good physical condition can only feel the symptoms of anemia in severe cases, with hemoglobin around 6 g/dl. Older people may begin to feel the effects when hemoglobin levels drop below 10 g/dl.

In cases of acute anemia, with fast installation, such as occur by hemorrhage, the patient feels symptoms even though the decrease in hemoglobin is not very visible. Hemoglobin that drops abruptly to 14 g/dl to 10 g/dl is sufficient to cause many of the symptoms of anemia described above.

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