Anemia: Symptoms and Causes

Updated: June 16, 2022

Anemia is a medical condition in which the red blood cell count or hemoglobin is less than normal. Hemoglobin is a main part of red blood cells which binds oxygen and carry it to the tissues. If your red blood cell count is low or your hemoglobin is low, the cells in your body will not get enough oxygen.
Anemia is caused by either a decrease in production of red blood cells or hemoglobin, or an increase in loss due to bleeding or destruction of red blood cells. Anemia is usually defined as hemoglobin level of less than 13.5 gram/100 ml in men and less than 12.0 gram/100 ml in women.

Symptoms of Anemia :

Signs and symptoms vary depending on the cause of your anemia. They may include:

•     Fatigue
•     Weakness
•     Hair loss
•     Pale or yellowish skin
•     Irregular heartbeats
•     Shortness of breath
•     Dizziness or lightheadedness
•     Chest pain
•     Cold hands and feet
•     Headache

In acute anemia, the patient may experience significant symptoms relatively quickly, and even with relative mild fluctuations of hemoglobin levels. But in case of chronic anemia, the body may adjust to low oxygen levels and the individual may not feel any symptoms unless the anemia becomes severe.

Function of Red Blood Cells:

Three types of blood cells are produced in the body. White blood cells to fight infection, platelets to help blood clot and red blood cells to carry oxygen throughout the body. Red blood cells contain hemoglobin which is an iron-rich protein. This gives blood its red color. Hemoglobin enables red blood cells to carry oxygen from the lungs to all parts of the body and to carry carbon dioxide from other parts of the body to your lungs so that it can be exhaled.
Red blood cells as well as other blood cells are produced regularly in the bone marrow which is a spongy material found within the cavities of large bones. Your body needs iron, vitamin B-12, folate and other nutrients from the foods you eat to produce hemoglobin and red blood cells.

Causes of Anemia:

Causes of anemia can be divided in to three groups. These are:

• Anemia caused by blood loss
• Anemia caused by decreased or faulty red blood cell production
• Anemia caused by destruction of red blood cells

Anemia Caused by Blood Loss :

Red blood cells can be lost through bleeding which could be because of one of the following conditions.

• Gastrointestinal conditions such as ulcers, hemorrhoids, gastritis, and cancer
• Use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen, which can cause ulcers and gastritis
• Menstruation and childbirth in women, especially if menstrual bleeding is excessive and if there are multiple pregnancies

Anemia Caused by Decreased or Faulty Red Blood Cell Production :

The body may produce too few blood cells or the blood cells may not function correctly with this type of anemia. If there is a lack of minerals and vitamins needed for red blood cells to work properly, red blood cells may be faulty or decreased. This may be due to abnormal red blood cells also.
These causes of anemia could be due to one of the following conditions:

•     Sickle cell anemia
•     Iron-deficiency anemia
•     Vitamin deficiency
•     Bone marrow and stem cell problems
•     Other health conditions

Anemia Caused by Destruction of Red Blood Cells :

This type of anemia is known as hemolytic anemia where the red blood cells rupture prematurely, because they are fragile and cannot withstand the routine stress of the circulatory system.
Causes of hemolytic anemia may include:

• Inherited conditions, such as sickle cell anemia and thalassemia
• Stressors such as  drugs, infections, snake or spider venom, or certain foods
• Vascular grafts, tumors, prosthetic heart valves, severe burns, exposure to certain chemicals, severe hypertension, and clotting disorders
• Toxins from advanced liver or kidney disease
• Inappropriate attack by the immune system called hemolytic disease of the newborn when it occurs in the fetus of a pregnant woman
• In rare cases, an enlarged spleen can trap red blood cells and destroy them before their circulating time is up.