Q. Is low iron a problem if there are no symptoms of anemia?
A. The classic symptom of iron-deficiency anemia is feeling tired or weak, though other symptoms include headaches, shortness of breath, sensitivity to cold or even depression. Still, you might not experience any symptoms until the anemia is quite severe, said Dr. Nancy Berliner, the deputy editor of the American Society of Hematology’s journal Blood. But since low iron is caused by loss of iron-rich blood, it means you’re bleeding somewhere, so “you don’t want to ignore it,” she said.
You may be iron deficient without being anemic, but since your body needs iron to make the hemoglobin in red blood cells, anemia may be just down the road. “Most people who are losing enough iron to become deficient will continue to lose and become anemic,” said Dr. Berliner, who is also chief of hematology at Brigham and Women’s Hospital in Boston.
There are several ways to test for iron deficiency, but the best measure is a test for blood levels of ferritin, the storage form of iron, she said.
Women who have heavy periods are frequently iron-deficient, and pregnancy can cause iron deficiency that should be treated.
For women who are not menstruating and men, however, the most common cause of iron deficiency is gastrointestinal bleeding, which could be a sign of colorectal cancer or a precancerous polyp, or could be caused by ulcers or gastritis related to the use of drugs like aspirin, Dr. Berliner said. Some surgical procedures, such as bariatric surgery, can prevent iron absorption from the gut, resulting in a deficiency.
Strict vegans may become iron deficient if they don’t consume enough iron over an extended period of time; beans, leafy greens, dried fruits and seeds are good sources of iron.
Taking iron supplements can correct the anemia, but Dr. Berliner emphasized that it’s important to identify the underlying reason for the blood loss, which may require medical tests like endoscopy or colonoscopy to look for polyps or other problems.