Organs commonly affected by haemochromatosis are the liver, heart, and endocrine glands.

Haemochromatosis may present with the following clinical syndromes:

- Cirrhosis of the liver: Varies from zonal iron deposition to fibrosis (cirrhosis).

- Diabetes due to selective iron deposition in pancreatic islet beta cells leading to functional failure and cell death.

- Cardiomyopathy

- Arthritis, from calcium pyrophosphate deposition in joints. The most commonly affected joints are those of the hands, particularly the knuckles of the second and third fingers.

- Testicular failure

- Bronzing of the skin. This deep tan color, in concert with insulin insufficiency due to pancreatic damage, is the source of a nickname for this condition: "bronze diabetes".

- Joint pain and bone pain

The presentation of this disorder entails anemia, arthritis, hepatic anomalies, and recurrent infections are clinical signs of the disease. Iron overload occurs mainly in the liver, heart, pancreas, thyroid, and kidney

Iron is stored in the liver, the pancreas and the heart. Long-term effects of haemochromatosis on these organs can be very serious, even fatal when untreated. For example, similar to alcoholism, haemochromatosis can cause cirrhosis of the liver. The liver is a primary storage area for iron and will naturally accumulate excess iron. Over time the liver is likely to be damaged by iron overload. Cirrhosis itself may lead to additional and more serious complications, including bleeding from dilated veins in the esophagus (esophageal varices) and stomach (gastric varices) and severe fluid retention in the abdomen (ascites). Toxins may accumulate in the blood and eventually affect mental functioning. This can lead to confusion or even coma (hepatic encephalopathy).

Liver cancer: Cirrhosis and haemochromatosis together will increase the risk of liver cancer. (Nearly one-third of people with haemochromatosis and cirrhosis eventually develop liver cancer.)

Diabetes: The pancreas which also stores iron is very important in the body’s mechanisms for sugar metabolism. Diabetes affects the way the body uses blood sugar (glucose). Diabetes is in turn the leading cause of new blindness in adults and may be involved in kidney failure and cardiovascular disease.

Congestive heart failure: If excess iron in the heart interferes with the its ability to circulate enough blood, a number of problems can occur, even death. The condition may be reversible when haemochromatosis is treated and excess iron stores reduced.

Heart arrhythmias: Arrhythmia or abnormal heart rhythms can cause heart palpitations, chest pain and light-headedness and are occasionally life-threatening. This condition can often be reversed with treatment for haemochromatosis.

Pigment changes: Bronze or grey coloration of the skin is caused primarily by increased melanin deposition, with iron deposition playing a lesser role.

Haemochromatosis is in its manifestations, "i.e.", often presenting with signs or symptoms suggestive of other diagnoses that affect specific organ systems. Many of the signs and symptoms below are uncommon and most patients with the hereditary form of haemochromatosis do not show any overt signs of disease nor do they suffer premature morbidity.

The classic triad of cirrhosis, bronze skin and diabetes is not as common any more because of earlier diagnosis.

The more common clinical manifestations include:

- Fatigue

- Malaise

- Joint and bone pain

- Liver cirrhosis (with an increased risk of hepatocellular carcinoma) Liver disease is always preceded by evidence of liver dysfunction including elevated serum enzymes specific to the liver, clubbing of the fingers, leuconychia, asterixis, hepatomegaly, palmar erythema and spider naevi. Cirrhosis can also present with jaundice (yellowing of the skin) and ascites.

- Insulin resistance (often patients have already been diagnosed with diabetes mellitus type 2) due to pancreatic damage from iron deposition

- Erectile dysfunction and hypogonadism, resulting in decreased libido

- Congestive heart failure, abnormal heart rhythms or pericarditis

- Arthritis of the hands (especially the second and third MCP joints), but also the knee and shoulder joints

- Damage to the adrenal gland, leading to adrenal insufficiency

Less common findings including:

- Deafness

- Dyskinesias, including Parkinsonian symptoms

- Dysfunction of certain endocrine organs:

- Parathyroid gland (leading to hypocalcaemia)

- Pituitary gland

- More commonly a slate-grey or less commonly darkish colour to the skin (see pigmentation, hence its name "diabetes bronze" when it was first described by Armand Trousseau in 1865)

- An increased susceptibility to certain infectious diseases caused by siderophilic microorganisms:

- "Vibrio vulnificus" infections from eating seafood or wound infection

- "Listeria monocytogenes"

- "Yersinia enterocolica"

- "Salmonella enterica" (serotype Typhymurium)

- "Klebsiella pneumoniae"

- "Escherichia coli"

- "Rhizopus arrhizus"

- "Mucor" species

Males are usually diagnosed after their forties and fifties, and women several decades later, owing to regular iron loss through menstruation (which ceases in menopause). The severity of clinical disease in the hereditary form varies considerably. There is evidence suggesting that hereditary haemochromatosis patients affected with other liver ailments such as hepatitis or alcoholic liver disease suffer worse liver disease than those with either condition alone. There are also juvenile forms of hereditary haemochromatosis that present in childhood with the same consequences of iron overload.

Iron overload, also known as haemochromatosis, indicates accumulation of iron in the body from any cause. The most important causes are hereditary haemochromatosis (HHC), a genetic disorder, and transfusional iron overload, which can result from repeated blood transfusions.

Atransferrinemia, also called familial hypotransferrinemia, is an autosomal recessive metabolic disorder in which there is an absence of transferrin, a plasma protein that transports iron through the blood.

Atransferrinemia is characterized by anemia and hemosiderosis in the heart and liver. The iron damage to the heart can lead to heart failure. The anemia is typically microcytic and hypochromic (the red blood cells are abnormally small and pale). Atransferrinemia was first described in 1961 and is extremely rare, with only ten documented cases worldwide.

Another common symptom of copper deficiency is peripheral neuropathy, which is numbness or tingling that can start in the extremities and can sometimes progress radially inward towards the torso. In an Advances in Clinical Neuroscience & Rehabilitation (ACNR) published case report, a 69-year-old patient had progressively worsened neurological symptoms. These symptoms included diminished upper limb reflexes with abnormal lower limb reflexes, sensation to light touch and pin prick was diminished above the waist, vibration sensation was lost in the sternum, and markedly reduced proprioception or sensation about the self’s orientation. Many people suffering from the neurological effects of copper deficiency complain about very similar or identical symptoms as the patient. This numbness and tingling poses danger for the elderly because it increases their risk of falling and injuring themselves. Peripheral neuropathy can become very disabling leaving some patients dependent on wheel chairs or walking canes for mobility if there is lack of correct diagnosis. Rarely can copper deficiency cause major disabling symptoms. The deficiency will have to be present for an extensive amount of time until such disabling conditions manifest.

Some patients suffering from copper deficiency have shown signs of vision and color loss. The vision is usually lost in the peripheral views of the eye. The bilateral vision loss is usually very gradual. An optical coherence tomography (OCT) shows some nerve fiber layer loss in most patients, suggesting the vision loss and color vision loss was secondary to optic neuropathy or neurodegeneration.

Symptoms can vary from one person to another. It depends on the extent of accumulation and on the body location of the accumulation. African iron overload can be considered in patient with some of these conditions.

Genes involved in iron metabolism disorders include HFE and TFR2.

Hepcidin is the master regulator of iron metabolism and, therefore, most genetic forms of iron overload can be thought of as relative hepcidin deficiency in one way or another. For instance, a severe form of iron overload, juvenile hemochromatosis, is a result of severe hepcidin deficiency. The majority of cases are caused by mutations in the hemojuvelin gene (HJV or RGMc/repulsive guidance molecule c). The exceptions, people who have mutations in the gene for ferroportin, prove the rule: these people have plenty of hepcidin, but their cells lack the proper response to it. So, in people with ferroportin proteins that transport iron out of cells without responding to hepcidin's signals to stop, they have a deficiency in the action of hepcidin, if not in hepcidin itself.

But the exact mechanisms of most of the various forms of adult hemochromatosis, which make up most of the genetic iron overload disorders, remain unsolved. So while researchers have been able to identify genetic mutations causing several adult variants of hemochromatosis, they now must turn their attention to the normal function of these mutated genes.

These genes represent multiple steps along the pathway of iron regulation, from the body's ability to sense iron, to the body's ability to regulate uptake and storage. Working out the functions of each gene in this pathway will be an important tool for finding new methods of treating genetic disorders, as well as for understanding the basic workings of the pathway.

So though many mysteries of iron metabolism remain, the discovery of hepcidin already allows a much better understanding of the nature of iron regulation, and makes researchers optimistic that many more breakthroughs in this field are soon to come.

Porphyria cutanea tarda (commonly referred to as PCT) is recognized as the most prevalent subtype of porphyritic diseases.

The disease is characterized by onycholysis and blistering of the skin in areas that receive higher levels of exposure to sunlight. The primary cause of this disorder is a deficiency of uroporphyrinogen decarboxylase (UROD), a cytosolic enzyme that is a step in the enzymatic pathway that leads to the synthesis of heme. While a deficiency in this enzyme is the direct cause leading to this disorder, there are a number of both genetic and environmental risk factors that are associated with PCT.

Typically, patients who are ultimately diagnosed with PCT first seek treatment following the development of photosensitivities in the form of blisters and erosions on commonly exposed areas of the skin. This is usually observed in the face, hands, forearms, and lower legs. It heals slowly and with scarring. Though blisters are the most common skin manifestations of PCT, other skin manifestations like hyperpigmentation (as if they are getting a tan) and hypertrichosis (mainly on top of the cheeks) also occur. PCT is a chronic condition, with external symptoms often subsiding and recurring as a result of a number of factors. In addition to the symptomatic manifestation of the disease in the skin, chronic liver problems are extremely common in patients with the sporadic form of PCT. These include hepatic fibrosis (scarring of the liver), cirrhosis, and inflammation. However, liver problems are less common in patients with the inherited form of the disease. Additionally, patients will often void a wine-red color urine with an increased concentration of uroporphyrin I due to their enzymatic deficiency.

Patients with aceruloplasminemia develop a variety of movement problems. They may experience dystonia of the head and neck, resulting in repetitive movements and contortions. Other involuntary movements may also occur, such as tremors, chorea, blepharospasms, and grimacing. Affected individuals may also experience ataxia, the lack of coordination of muscle movements. Some develop psychiatric problems and midlife dementia. The type of neurological disruption corresponds to associated regions of iron deposition in the brain and liver.

In addition to neurological problems, affected individuals may have diabetes mellitus caused by iron damage to cells in the pancreas that make insulin. This impairs blood sugar regulation and leads to the signs and symptoms of diabetes.

Iron accumulation in the tissues and organs results in a corresponding iron deficiency in the blood, leading to anemia. Anemia and diabetes usually occur by the time an affected person is in his or her twenties.

Affected individuals also experience retinal degeneration caused by excess iron. The changes result in small opaque spots and areas of atrophy around the edges of the retina. These abnormalities usually do not affect vision but can be observed during an eye examination.

African iron overload, also known as (Bantu siderosis, or Dietary iron overload), is an iron overload disorder first observed among people of African descent in Southern Africa and Central Africa.

Dietary iron overload is the consumption of large amount of home-brewed beer with high amount of iron content in it. Preparing beer in iron pots or drums results in high iron content. The iron content in home-brewed beer is around 46–82 mg/l compared to 0.5 mg/l in commercial beer. Dietary overload was prevalent in both the rural and urban Black African population, with the introduction of commercial beer in urban areas, the condition has decreased. However, the condition is still common in rural areas. Until recently, studies have shown that genetics might play a role in this disorder. Combination of excess iron and functional changes in ferroportin seems to be the probable cause. This disorder can be treated with phlebotomy therapy or (iron-chelation) therapy.

Aceruloplasminemia is a rare autosomal recessive disorder in which iron gradually accumulates in the retina, basal ganglia, and other organs. Iron accumulation in the brain results in neurological problems that generally appear in adulthood and worsen over time.

Aceruloplasminemia has been seen worldwide, but its overall prevalence is unknown. Studies in Japan have estimated that approximately 1 in 2 million adults in this population are affected.

Aceruloplasminemia belongs to the group of genetic disorders called neurodegeneration with brain iron accumulation (NBIA).

Transfusional hemosiderosis is the accumulation of iron in the liver and heart but also endocrine organs, in patients who receive or did receive frequent blood transfusions (such as those with thalassemia, sickle cell disease, leukemia, aplastic anemia or myelodysplastic syndrome).

Hemosiderosis (AmE) or haemosiderosis (BrE) is a form of iron overload disorder resulting in the accumulation of hemosiderin.

Types include:

- Transfusion hemosiderosis

- Idiopathic pulmonary hemosiderosis

- Transfusional diabetes

Hemosiderin deposition in the lungs is often seen after diffuse alveolar hemorrhage, which occurs in diseases such as Goodpasture's syndrome, granulomatosis with polyangiitis, and idiopathic pulmonary hemosiderosis. Mitral stenosis can also lead to pulmonary hemosiderosis. Hemosiderin collects throughout the body in hemochromatosis. Hemosiderin deposition in the liver is a common feature of hemochromatosis and is the cause of liver failure in the disease. Selective iron deposition in the beta cells of pancreatic islets leads to diabetes due to distribution of transferrin receptor on the beta cells of islets and in the skin leads to hyperpigmentation. Hemosiderin deposition in the brain is seen after bleeds from any source, including chronic subdural hemorrhage, cerebral arteriovenous malformations, cavernous hemangiomata. Hemosiderin collects in the skin and is slowly removed after bruising; hemosiderin may remain in some conditions such as stasis dermatitis. Hemosiderin in the kidneys has been associated with marked hemolysis and a rare blood disorder called paroxysmal nocturnal hemoglobinuria.

Hemosiderin may deposit in diseases associated with iron overload. These diseases are typically diseases in which chronic blood loss requires frequent blood transfusions, such as sickle cell anemia and thalassemia, though beta thalassemia minor has been associated with hemosiderin deposits in the liver in those with non-alcoholic fatty liver disease independent of any transfusions.

Haemochromatosis type 3 is a type of Iron overload disorder associated with deficiencies in transferrin receptor 2. It exhibits an autosomal recessive inheritance pattern.

Porphyria cutanea tarda (PCT) is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fifth step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood.

Hepatoerythropoietic porphyria has been described as a homozygous form of porphyria cutanea tarda, although it can also be caused if two different mutations occur at the same locus.

Many affected individuals have yellowing of the skin and eyes (jaundice) and an enlarged liver and spleen (hepatosplenomegaly). This condition also causes the body to absorb too much iron, which builds up and can damage tissues and organs. In particular, iron overload can lead to an abnormal heart rhythm (arrhythmia), congestive heart failure, diabetes, and chronic liver disease (cirrhosis). Rarely, people with CDA type I are born with skeletal abnormalities, most often involving the fingers and/or toes.

Three main forms have been described: thalassemia major, thalassemia intermedia, and thalassemia minor. All people with thalassemia are susceptible to health complications that involve the spleen (which is often enlarged and frequently removed) and gallstones. These complications are mostly found in thalassemia major and intermedia patients. Individuals with beta thalassemia major usually present within the first two years of life with severe anemia, poor growth, and skeletal abnormalities during infancy. Untreated thalassemia major eventually leads to death, usually by heart failure; therefore, birth screening is very important.

Excess iron causes serious complications within the liver, heart, and endocrine glands. Severe symptoms include liver cirrhosis, liver fibrosis, and in extreme cases, liver cancer. Heart failure, growth impairment, diabetes and osteoporosis are life-threatening contributors brought upon by TM. The main cardiac abnormalities seen to have resulted from thalassemia and iron overload include left ventricular systolic and diastolic dysfunction, pulmonary hypertension, valveulopathies, arrhythmias, and pericarditis. Increased gastrointestinal iron absorption is seen in all grades of beta thalassemia and increased red blood cell destruction by the spleen due to ineffective erythropoiesis further releases additional iron into the bloodstream.

Symptoms of iron deficiency can occur even before the condition has progressed to iron deficiency anemia.

Symptoms of iron deficiency are not unique to iron deficiency (i.e. not pathognomonic). Iron is needed for many enzymes to function normally, so a wide range of symptoms may eventually emerge, either as the secondary result of the anemia, or as other primary results of iron deficiency. Symptoms of iron deficiency include:

- fatigue

- dizziness/lightheadedness

- pallor

- hair loss

- twitches

- irritability

- weakness

- pica

- brittle or grooved nails

- hair thinning

- Plummer–Vinson syndrome: painful atrophy of the mucous membrane covering the tongue, the pharynx and the esophagus

- impaired immune function

- pagophagia

- restless legs syndrome

Continued iron deficiency may progress to anaemia and worsening fatigue. Thrombocytosis, or an elevated platelet count, can also result. A lack of sufficient iron levels in the blood is a reason that some people cannot donate blood.

GRACILE syndrome is a very rare autosomal recessive genetic disorder, one of the Finnish heritage diseases. It is caused by mutation in BCS1L gene that occurs in at least 1 out of 47,000 live births in Finnish people.

GRACILE is an acronym for growth retardation, amino aciduria (amino acids in the urine), cholestasis, iron overload, lactic acidosis, and early death. Other names for this syndrome include Finnish lethal neonatal metabolic syndrome (FLNMS); lactic acidosis, Finnish, with hepatic hemosiderosis; and Fellman syndrome.

Hereditary spherocytosis (also known as Minkowski–Chauffard syndrome) abnormality of erythrocytes. The disorder is caused by mutations in genes relating to membrane proteins that allow for the erythrocytes to change shape. The abnormal erythrocytes are sphere-shaped (spherocytosis) rather than the normal biconcave disk shaped. Dysfunctional membrane proteins interfere with the cell's ability to be flexible to travel from the arteries to the smaller capillaries. This difference in shape also makes the red blood cells more prone to rupture. Cells with these dysfunctional proteins are taken for degradation at the spleen. This shortage of erythrocytes results in hemolytic anemia.

It was first described in 1871 and is the most common cause of inherited hemolysis in Europe and North America within the Caucasian population, with an incidence of 1 in 5000 births. The clinical severity of HS varies from symptom-free

carrier to severe haemolysis because the disorder exhibits incomplete penetrance in its expression.

Symptoms include anemia, jaundice, splenomegaly, and fatigue. On a blood smear, Howell-Jolly bodies may be seen within red blood cells. Primary treatment for patients with symptomatic HS has been total splenectomy, which eliminates the hemolytic process, allowing normal hemoglobin, reticulocyte and bilirubin levels.

As in non-hereditary spherocytosis, the spleen destroys the spherocytes. This process of red blood cells rupturing directly results in varying degrees of anemia (causing a pale appearance and fatigue), high levels of bilirubin in the blood (causing jaundice), and splenomegaly.

Acute cases can threaten to cause hypoxia through anemia and acute kernicterus through high blood levels of bilirubin, particularly in newborns. Most cases can be detected soon after birth. An adult with this disease should have their children tested, although the presence of the disease in children is usually noticed soon after birth. Occasionally, the disease will go unnoticed until the child is about 4 or 5 years of age. A person may also be a carrier of the disease and show no signs or symptoms of the disease. Other symptoms may include abdominal pain that could lead to the removal of the spleen and/or gallbladder.

Chronic symptoms include anemia, increased blood viscosity, and splenomegaly, and some symptoms are still unknown at this stage. Furthermore, the detritus of the broken-down blood cells – unconjugated or indirect bilirubin – accumulates in the gallbladder, and can cause pigmented gallstones to develop. In chronic patients, an infection or other illness can cause an increase in the destruction of red blood cells, resulting in the appearance of acute symptoms, a "hemolytic crisis". Spherocytosis patients who are heterozygous for a hemochromatosis gene may suffer from iron overload despite the hemochromatosis genes being recessive.

One Finnish study which followed 25 cases from 18 families found that half the infants died within 3 days of birth and the other half died before 4 months of age.

Congenital dyserythropoietic anemia type I (CDA I) is a disorder of blood cell production, particularly of

the production of erythroblasts, which are the precursors of the red blood cells (RBCs).