Iron deficiency occurs when there is not enough mineral iron in the blood. If left untreated, it can lead to iron deficiency anemia, that is, a decrease in the number, size and function of red blood cells.

Athletes, especially women, usually suffer from iron deficiency. It is vital for athletic performance because it helps transport oxygen to your cells. It is also important for brain health and immune function. Knowing the symptoms of iron deficiency can help you prevent it from getting worse and turning into anemia.