We do not often pay much attention to the complexity of human blood but it is a lot more than just red fluid flowing through the blood vessels. Within blood is a host of different cells, carrier proteins, nutrients, gases, wastes and toxins. Blood is the medium through which all these different substances travel from one part of the body to another. If any component of blood is lacking or defective then certain essential processes throughout the body will be disrupted. One such problem is anemia.

Facts About Anemia

  • Anemia is a common blood disorder. It is a broad term that includes different types of abnormalities with red blood cells.
  • Red blood cells (erythrocytes) carry gases like oxygen through the bloodstream.
  • Iron-deficiency anemia is the most common type of anemia. It occurs when there is not enough iron in the body.
  • Iron is one of the most important component of red blood cells. Without sufficient iron, there are fewer red blood cells in the body and these blood cells may even be smaller in size than normal.
  • Iron-deficiency anemia means that your blood carries less oxygen than it normally would so the tissues in your body receives less oxygen.

Iron in the Human Body

Red Blood Cells
  • The total amount of iron in the body is around 3.5 grams (3 500mg) in men and about 2.5 grams (2 500mg) in women. In comparison, the total body iron in healthy newborn babies is around 0.25 grams (250mg).
  • Hemoglobin accounts for about 60% of the total body iron while ferritin (within the blood and in cells) accounts for another 20%.
  • Hemoglobin is the oxygen-carrying protein in red blood cells. It gives blood its red color. Ferritin is the protein that stores iron.
  • Men lose about 1mg of iron everyday whereas women lose about 2mg daily. However, the body is able to compensate for this loss by absorbing iron from food in the gut.
  • Women lose between 4mg to 100mg during each menstrual period and in the course of pregnancy, the average female loses as much as 500mg of iron.

Extreme Tiredness

Oxygen is an essential component for metabolism just as much as nutrients like glucose. Without oxygen the body cannot produce the same amount of energy. Naturally a person will feel more tired than normal. Initially this fatigue is noticeable only with activity. A person may tire quickly even with just moderate physical activity. As the anemia worsens tiredness is constant throughout the day and even after awaking from a restful sleep. Eventually weakness becomes apparent. It progresses to the point of extreme fatigue where a person is unable to complete daily activities and becomes apathetic.

Shortness of Breath

Since the blood has a lower oxygen-carrying capacity, due to less hemoglobin and too few red blood cells in iron-deficiency anemia, the tissues in the body are existing in a low oxygen state (hypoxia). Initially this is more of a problem when there is increased demand for oxygen. Even with moderate activity a person becomes short of breath and starts to breathe rapidly. As the anemia worsens a person may feel short of breath just with walking up a few stairs, moving around the house and eventually even at rest. Faster and deeper breathing is one way the body attempts to compensate by speeding up blood oxygenation but in time this is insufficient to alleviate the sensation of short breath.

Rapid Heart Rate

The heart receives deoxygenated blood from the body, sends it to the lung for re-oxygenation and then pushes out the oxygen-rich to the entire body. In a person with iron-deficiency anemia, the low oxygen state forces the body to compensate. The heart beats faster in an attempt to re-oxygenate blood more quickly and deliver the oxygen to the general circulation. This compensatory mechanism of the heart, along with rapid breathing, may be sufficient for short periods of time and in mild iron-deficiency anemia. However, with severe iron-deficiency anemia, even these mechanisms may not be adequate particularly during periods of increased oxygen demand like with physical activity.

Lightheaded and Dizzy

The brain is the most oxygen-sensitive tissue in the body. Low oxygen states initially presents with a lightheaded feeling which progresses to dizziness and eventually fainting (syncope) when the oxygen availability drops to a severely low level. A person with iron-deficiency anemia is living in a low oxygen state but it may be minor and the body is able to compensate (rapid heart rate and breathing) at first. In this instance a person may only feel slightly lightheaded at times or dizziness with physical activity when the body needs more oxygen. As the anemia worsens, the lightheaded feeling is constant and may progress to dizziness. Fainting episodes are not uncommon in severe anemia.

Pale Skin and Eyes

Hemoglobin gives blood its red color and blood flowing through the skin and whites of the eyes is partly responsible for its natural pigmentation. When the the hemoglobin levels are lower than normal, blood is less red in color. This is the reason that people with iron deficiency anemia have a slightly paler color of the skin and eyes. In addition, the blood is less viscous (less thick) with iron-deficiency anemia and this reduces the resistance within the blood vessels. In order to maintain blood pressure the vessels of the skin narrow,  further contributing to paleness of the skin as well as making the skin cold to touch especially of the hands and feet .

Brittle Hair and Nails

There are several changes that occur in different tissues due to iron-deficiency anemia. Brittle hair and nails are two common findings among people with iron-deficiency anemia. The exact reason behind these changes is not entirely understood. It may be a direct consequence of low iron levels associated with low ferritin or the low oxygen-carrying capacity of the blood. Or it may be a secondary effect of iron deficiency anemia possibly linked to a hormonal mechanism. Apart from being brittle, the hair and nails also show other chances. Hair may also become dry and lacks a natural luster with increased hair loss in some iron-deficiency patients. The nails may develop vertical ridges and with severe anemia it can become concave or spoon-shaped (koilonychia).


Article reviewed by Dr. Greg. Last updated on February 6, 2013