Causes of low iron in the blood, also known as iron deficiency anemia, include a lack of iron in the diet and blood loss during menstruation or as the result of a peptic ulcer, colon polyp or hiatal hernia, according to Mayo Clinic. Pregnancy can also cause low iron in the blood because the increased blood volume of the mother and fetus consume the iron stores within the body.
Some people have low iron in the blood because their bodies have an inability to absorb iron due to an intestinal disorder, explains Mayo Clinic. Conditions such as celiac disease distort the intestine's ability to absorb necessary nutrients from food that is digested.
People with low iron in the blood often feel dizzy, weak and fatigued, according to WebMD. Some patients experience headaches, feel short of breath, look pale and have difficulty concentrating. An iron deficiency is often diagnosed by a physician through physical exams and blood tests. Blood tests can reveal the complete blood count to determine how much iron is in the blood.
Treatment for iron deficiency is often focused on the condition causing the lack of iron, explains Mayo Clinic. Many physicians recommend iron supplements to increase the amount of iron in the blood.