Patient-Friendly Explanation

Therapeutic phlebotomy means deliberately removing a small amount of blood, much like a blood donation. It is used mainly to bring down too much iron in the body, and in people with metabolic syndrome it can also improve blood sugar handling and blood pressure a little.

Clinical Definition

Phlebotomy reduces circulating iron stores by lowering ferritin and transferrin saturation. Iron depletion has been shown to modestly improve insulin sensitivity, HbA1c, fasting glucose and blood pressure in patients with hyperferritinaemia and metabolic dysfunction, plausibly by reducing oxidative stress and hepatic iron loading. It is established therapy for hereditary haemochromatosis and porphyria cutanea tarda, and is used in polycythaemia; monitoring of haemoglobin, ferritin and blood pressure during a course is essential.

Why It Matters

Raised ferritin is common in obesity and fatty liver and is easily missed, so patients with metabolic syndrome and repeatedly high iron studies may benefit from referral. Phlebotomy is a supportive measure alongside diet, activity and medical weight management, not a replacement for them.