Table 5.

The iron overload clinical conditions discussed in the article, in which one of the leading symptoms is fatigue.

Name of Disease	Brief Description of the Disease
Hereditary hemochromatosis	It is a genetic disease in 80% based on HFE-gene mutation, leading to increased accumulation of iron in body tissues, resulting in the generation of oxidative stress and damage to many organs. Cirrhosis, diabetes, and dark skin color were the main symptoms of HH before the era of HFE gen revealing [100]. An introduction of genetic tests in patients with abnormal iron management parameters to routine clinical practice makes it possible to diagnose HH early before the patients demonstrate symptoms of advanced diseases. Instead of the above-mentioned classic triad, one of the early symptoms noticed by patients with HH is the feeling of severe, chronic fatigue, which very often significantly decreases the quality of life. The treatment of choice for hereditary hemochromatosis are venesections. Treatment performed at the appropriate frequency significantly reduces fatigue, ferritin, and iron [109]. Venesections are more effective in reducing iron levels than chelating drugs [100]. Additionally, the applied treatment significantly improves the function of the heart muscle [109,114].
Beta-thalassemia	It is one of the genetically determined (mutation of genes located on chromosome 11) hemolytic anemia resulting from a disturbance in the synthesis of hemoglobin beta chains [115]. There are three groups of β-thalassemia: minor, intermedia, and major. Beta thalassemia major is the most severe form of beta-thalassemia. Severe symptoms of hemolytic anemia may appear already after six months of age and require treatment by regular red blood cell transfusions and sometimes chelation therapy [115]. Beta-thalassemia intermedia is a milder form of the disease.
Sideroblastic anemia	It is a group of congenital and acquired diseases characterized by the presence of peripheral microcytic anemia in the blood and an image of ring sideroblasts in the bone marrow (iron overloaded mitochondria surround erythroblast nuclei) [116].
Congenital dyserythropoietic anemias (CDA)	It is a group of rarely diagnosed anemia of unknown etiology, characterized by increased ineffective erythropoiesis, multinuclear erythroblast nuclei in the marrow, and secondary iron accumulation in tissues. Abnormal erythroblasts are destroyed in the bone marrow, resulting in elevated serum bilirubin and LDH levels [117]. The classification considers three types of CDA. In types I and III, CDA macrocytes are present, while type II CDA is characterized by normocytosis. Anemia is usually mild to moderate and manifests itself at different times in life.