Low ferritin levels indicate that the bodys iron stores are low and can lead to iron-deficiency anemia. Iron deficiency can come from a poor diet, blood loss, or the bodys inability to absorb iron from food. Some of the most common causes of iron deficiency anemia are bleeding in the stomach and intestines, heavy menstrual periods, and pregnancy. Low ferritin levels may also be caused by decreased iron intake, low gastrointestinal absorption, Crohns disease, ulcerative colitis, celiac disease, hemorrhoids, colon cancer, peptic ulcer, menorrhagia, and hematuria.

If a ferritin test reveals that the blood ferritin level is lower than normal, it indicates iron deficiency, and the doctor will work to determine the cause. The normal range for blood ferritin is 24 to 336 micrograms per liter for men and 11 to 307 micrograms per liter for women. Symptoms of low ferritin levels include shortness of breath, irritability, dizziness, unexplained fatigue, ringing in the ears, pale, dry skin, heart palpitations, and increased hair shedding.

To diagnose iron deficiency anemia, a blood sample is taken from a vein in the arm, and a full blood count is made. If the person has anemia, the doctor may also test for a substance called ferritin, a protein that stores iron. If the ferritin levels are low, the doctor will work to determine the cause.