Anemia and Low Iron: Symptoms, Causes and Blood Tests

What it involves

NHLBI defines anemia as a condition that develops when your blood produces a lower-than-normal amount of healthy red blood cells, so your body does not get enough oxygen-rich blood. MedlinePlus says iron deficiency anemia, which occurs when your body does not have enough iron to make hemoglobin, is the most common form. Anemia is a finding with a cause behind it, and finding that cause is the point of the visit.

Who this is for

• Patients with ongoing tiredness, weakness, dizziness, or shortness of breath that has no clear cause
• Patients with heavy or long menstrual periods, or who are pregnant or breastfeeding
• Patients with a lab report that shows low hemoglobin, hematocrit, or ferritin
• Patients who take aspirin or similar medicines regularly or have stomach or bowel symptoms

What to expect

• Questions about energy, diet, periods, stool color, and any medicines or supplements you take
• A physical exam and a blood draw, often starting with a complete blood count
• Each result explained in plain words, including which numbers point to iron and which do not
• A plan to find the cause, since the cause decides the treatment

Symptoms, and why many people have none

NHLBI says the lack of oxygen can make you feel tired or weak and can bring shortness of breath, dizziness, headaches, or an irregular heartbeat. MedlinePlus adds that mild iron deficiency anemia may cause no symptoms, and that symptoms are usually mild at first and develop slowly. As it worsens, MedlinePlus lists pale skin, brittle nails, lightheadedness when you stand, a sore tongue, hair loss, restless legs, and a craving to chew ice. Because the onset is gradual, many people only notice after a routine blood test. Anemia is also on MedlinePlus's list of medical causes of hair loss, as the hair loss guide explains. MedlinePlus lists anemia among the conditions that can show up as ringing in the ears, and the tinnitus guide explains what else to review at a visit.

Why the body runs low on iron

MedlinePlus gives four broad reasons: Long-term blood loss can lower iron levels, and the hemorrhoids guide explains one common source of rectal bleeding and why it still needs to be checked.

• You lose more blood and iron than your body can replace, such as heavy periods or bleeding in the digestive tract
• Your body does not absorb iron well, as with celiac disease, Crohn disease, or gastric bypass surgery
• You are not eating enough foods that contain iron
• Your body needs more iron than usual, such as during pregnancy or breastfeeding

Blood tests that sort it out

MedlinePlus says diagnosis may start with a complete blood count and a reticulocyte count, and that iron levels can be checked with a serum iron level, total iron binding capacity, and serum ferritin. The complete blood count guide explains the first test line by line. Because B12 and folate shortages also cause anemia, the vitamin D and B12 blood tests page covers a related check. NHLBI also names vitamin B12 deficiency and hemolytic anemia as other types.

Finding the cause is the real work

NHLBI says anemia may be a sign of a more serious condition, such as bleeding in your stomach, inflammation from an infection, kidney disease, cancer, or autoimmune disease. MedlinePlus says to contact your provider if you notice blood or a black, tar-like appearance in your stool. In an adult with iron deficiency, the question of where iron is being lost matters, which is one reason the colorectal cancer screening guide belongs in the conversation for adults who are due.

Treatment depends on the type

NHLBI says treatment depends on the type and how serious it is, and may include iron supplements, vitamins, or medicines that help the body make more red blood cells, along with healthy eating changes. MedlinePlus says providers usually measure iron before starting supplements, that anemia often improves with six weeks of iron therapy, and that iron is usually continued for about six months to rebuild stores. It lists nausea, vomiting, and constipation as possible side effects. Do not start iron on your own before the cause is known.

Iron-rich foods and what helps absorption

MedlinePlus lists chicken, turkey, fish, meats (liver is the highest source), lentils, peas, beans, soybeans, chickpeas, whole-grain bread, spinach, kale, and dried fruits among iron sources. It says vitamin C helps the body absorb iron, naming oranges, grapefruit, kiwi, strawberries, broccoli, and tomatoes. Food is a support, not a substitute for finding the cause. Anyone feeling tired for weeks can also read the fatigue and tiredness evaluation for the other causes a provider considers.

Sources

• NHLBI — Anemia
• MedlinePlus — Iron deficiency anemia