Excess Iron (Poisoning, Overload, Toxicity) in Blood

Hemosiderosis is a chronic iron overload or excess iron levels in body tissues, either throughout the body or only in specific tissues and organs. If this chronic overload begins to cause tissue damage, it is known as hemochromatosis or commonly referred to as iron toxicity.

Iron is an abundant element in the human body and in conjunction with proteins, it forms hemoglobin, an essential compound in red blood cells that is responsible for gas transport (oxygen and carbon dioxide) in the blood. However excess iron intake or abnormal iron deposition can cause an iron overload (hemosiderosis) and eventual iron toxicity (hemochromatosis) if not attended to in the acute stages.

Causes of Iron Poisoning, Iron Overload & Iron Toxicity

Iron supplements where iron exists as ferrous sulphate or ferrous gluconate, multivitamins with iron and carbonyl iron (an iron plus carbon monoxide combination) can cause iron overload if used excessively (iron poisoning). This iron intake will usually not result in hemosiderosis or hemochromatosis if used in excess over a short period but may cause some acute symptoms of iron poisoning. Long term intake of excessive iron supplements however will result in hemosiderosis (iron overload) which may then be followed by hemochromatosis (iron toxicity). Iron poisoning is one of the most common types of poisoning in children which may lead to death.

Other causes of hemosiderosis and hemochromatosis include :

  • Genetic disorders :
  1. Primary hemochromatosis is caused by a genetic abnormality resulting in increased iron absorption from food.
  2. Y-linked hypochromic anemia
  3. Iron transport deficiency anemia (atransferrinemia). Refer to Blood Iron Levels for more information.
  4. Thalassemia major
  • Increased iron intake apart from iron ingestion.
  • Repeated blood transfusions.
  • African iron overload (1)
  • Kashin-Beck disease (2)
  • Excess intake of vitamin C may be linked to iron overload.

Signs & Symptoms of Iron Overload & Toxicity

Acute iron poisoning causes a number of gastrointestinal and systemic signs and symptoms which may also be present in hemosiderosis and hemochromatosis.

  • Diarrhea
  • Vomiting
  • Upper abdominal pain
  • Paleness of the skin (pallor) or even a bluish tinge (cyanosis)
  • Drowsiness
  • Shock

Other signs and symptoms associated with chronic iron overload (hemosiderosis) or iron toxicty (hemochromatosis) include :

  • Chronic abdominal pain
  • Abnormal skin pigmentation, usually yellow to bronze
  • Liver cirrhosis
  • Cardiac disorders including cardiomegaly (‘enlarged heart’), arrhythmias  or even cardiac failure.
  • Arthritis
  • Loss of libido
  • Shrinking of the testes (atrophy)
  • Pituitary failure

The body attempts to rid the system of the excess iron and may attempt excreting iron through the lungs or kidneys. This may not cause damage to lung or kidney tissue but may result in anemia (low blood iron)

Diagnosis of Iron Poisoning, Overload and Toxicity

The presence of the signs and symptoms of iron poisoning coupled with a case history revealing excess iron intake is usually sufficient for a differential diagnosis of iron poisoning. However these signs and symptoms of iron poisoning can also be attributed to other conditions and blood tests are required to confirm diagnosis. In terms of iron overload and toxicity, the severity and combination of signs and symptoms should be an indication of iron poisoning (hemochromatosis) and blood serum tests should be conducted immediately.

A liver biopsy may be necessary in suspected cases of liver cirrhosis, hepatoma or hepatocellular carcinoma.

Your medical practitioner will test serum iron levels, transferrin saturation as well as ferritin. Urine tests for iron may also indicate toxicity or poisoning. Family members may also be tested for HLA typing indicating possible genetic disorders causing primary hemochromatosis.

Treatment of Hemochromatosis and Hemosiderosis

Phlebotomy (blood drawing or letting of the blood) may be required to remove excess iron if increased iron levels in the blood is detected. Phlebotomy should be conducted by a medical practitioner in a controlled environment. Treatment may be required for other signs, symptoms or complications like diabetes mellitus or cardiac disorders. Iron supplementation should be discontinued immediately unless anemia is noted in cases of pulmonary or renal hemosiderosis.


1. Hepatocellular Carcinoma and African Iron Overload. Pubmed

2. Iron Overload. Pubmed

3. Primary Hemochromatosis. Merck

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