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

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.

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.

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.

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.

There are several methods available for diagnosing and monitoring hemosiderosis including:

- Serum ferritin

- Liver biopsy

- MRI

Serum ferritin is a low cost, readily available, and minimally invasive method for assessing body iron stores. However, the major problem with using it as an indicator of hemosiderosis is that it can be elevated in a range of other medical conditions unrelated to iron levels including infection, inflammation, fever, liver disease, renal disease and cancer.

While liver biopsies provide a direct measure of liver iron concentration, the small sample size relative to the size of the liver can lead to sampling errors given the heterogeneity of iron concentration within the liver. Furthermore, the invasive nature of liver biopsy and the associated risks of complications (which can range from pain, haemorrhage, gallbladder perforation and other morbidities through to death in approx 1 in 10,000 cases) prevent it being used as a regular monitoring tool.

MRI is emerging as an alternative method for measuring liver iron loading because it is non-invasive, safer and generally cheaper to perform than liver biopsy; does not suffer from problems with sampling variability; and can be used more frequently than performing liver biopsies.

Idiopathic pulmonary haemosiderosis (or idiopathic pulmonary hemosiderosis; IPH) is a lung disease of unknown cause that is characterized by alveolar capillary bleeding and accumulation of haemosiderin in the lungs. It is rare, with an incidence between 0.24 and 1.23 cases per million people.

Clinically, IPH manifests as a triad of haemoptysis, diffuse parenchymal infiltrates on chest radiographs, and iron deficiency anaemia. It is diagnosed at an average age of 4.5 plus or minus 3.5 years, and it is twice as common in females. The clinical course of IPH is exceedingly variable, and most of the patients continue to have episodes of pulmonary haemorrhage despite therapy. Death may occur suddenly from acute pulmonary haemorrhage or after progressive pulmonary insufficiency resulting in chronic respiratory failure.