In my own case this was explored because I was feeling fatigued all the time, not that I was cold, and I found that I am not anemic, my blood work is as normal as can be, and I do not have a thyroid or iron deficiency. Iron Deficiency Anemia (also called IDA) is a condition where a person has inadequate amounts of iron to meet body demands. It is a decrease in the amount of red cells in the blood caused by having too little iron. IDA is usually caused by a diet insufficient in iron or from blood loss. Blood loss can be acute as in hemorrhage or trauma or long term as in heavy menstruation. Iron is part of hemoglobin, the oxygen-carrying component of the blood. Iron-deficient people tire easily because their bodies are starved for oxygen. Iron is also part of myoglobin. Myoglobin helps muscle cells store oxygen. Without enough iron, the body's fuel cannot be properly synthesized. The main causes of iron deficiency are: poor absorption of iron by the body (Vitamin C aides in iron absorption), inadequate daily intake of iron, pregnancy, growth spurts or blood loss due to heavy periods or internal bleeding. Note that anemia after surgery should be very temporary and it is often used as an indicator that something is amiss within days of a surgical procedure.

Anemia develops slowly after the normal stores of iron have been depleted in the body and in the bone marrow. Women, in general, have smaller stores of iron than men. Women also loose iron more frequently than men because of the blood loss during menstruation.

In men and postmenopausal women, anemia may be due to gastrointestinal blood loss associated with ulcers, the use of aspirin or nonsteroidal anti-inflammatory medications (NSAIDS), or colon cancer. There are many symptoms of anemia. Each individual will not experience all the symptoms and if the anemia is mild, the symptoms may not be noticible. Some of the symptoms are: Pale skin color, fatigue, irritability, dizziness, weakness, shortness of breath, sore tongue, brittle nails, decreased appetite (especially in children), headache (frontal), blue tinge to sclerae (whites of eyes), and unusual food cravings (called pica). The inability to stay warm is not normally a symptom of anemia. Those that are hospitalized may, because of treatments or blood loss during treatments, develop short term anemia, and during that period of time, it may appear to be a contributing factor to a patients ability to feel warm. This blood loss anemia is not something that should occur in the normal population of survivors well out from all types of treatments. It may occur in those patients who still have blood issues related to surgical interventions, radiation, or chemotherapy, but not for those of us that are distant from these events.

While small suplimentations of iron will not hurt someone who is not iron deficient, too much of it can cause harm. Excess iron is toxic, causing vomiting, diarrhea, and damage to the intestine. Iron may accumulate in the body when a person is given iron therapy in excessive amounts or for too long, receives repeated blood transfusions, or has chronic alcoholism.