Iron Profile (TIBC, Serum Iron, Transferrin saturation)

A TIBC/transferrin saturation test measures how much iron blood proteins can carry and the percentage of that capacity actually filled. It compares serum iron to total iron‑binding capacity (TIBC) to assess iron status. It helps diagnose iron deficiency, chronic disease anemia, or iron overload (hemochromatosis). It’s a routine blood test often ordered with ferritin and CBC.

Low transferrin saturation means a smaller proportion of transferrin — the blood protein that carries iron — is bound to iron. It commonly indicates iron deficiency or poor iron transport from stores, and can signal early iron‑deficiency anemia or chronic inflammation. Symptoms include fatigue, weakness and pallor. Doctors usually order ferritin and CBC to confirm the cause and may recommend dietary changes, iron supplements, or treating underlying conditions.

Low total iron‑binding capacity (TIBC) means reduced transferrin and a diminished capacity to bind circulating iron. It’s commonly seen with inflammation/chronic disease, liver disease, malnutrition, nephrotic syndrome or iron overload. It usually accompanies normal/high ferritin and can mask iron deficiency. Management targets the underlying condition and correcting iron balance based on further testing.

Dangerously low iron is usually indicated by serum ferritin below about 15 ng/mL, which reflects iron deficiency. Severe deficiency often coexists with anemia — hemoglobin under about 8 g/dL (especially below 7 g/dL) is critical and may need urgent treatment. Seek immediate care if low iron causes chest pain, severe breathlessness, fainting, rapid heartbeat, or extreme weakness.

High TIBC typically reflects iron deficiency from chronic blood loss. Cancers that commonly cause this include gastrointestinal tumors (colorectal, gastric, esophageal), gynecologic cancers with uterine or vaginal bleeding (endometrial, cervical), and genitourinary malignancies that cause hematuria (bladder, renal). Most other cancers cause anemia of chronic disease, which usually lowers TIBC.

Early signs of iron deficiency include persistent fatigue and weakness, pale skin and inner eyelids, shortness of breath or rapid heartbeat with activity, dizziness or lightheadedness, frequent headaches, cold hands and feet, brittle or spoon-shaped nails, hair thinning, reduced concentration and irritability, and unusual cravings for non-food items (pica). See a clinician for testing if suspected.