The natural history of HH includes three phases:

- a phase of latency,

- a phase of biochemical expression, which appears around the age of 20, and which is characterised by an increase of iron parameter levels (serum iron, transferrin saturation, serum ferritin),

- a phase of clinical expression, which appears later during adulthood, generally around the age of 40 in males and later in females, around the age of 50, because of the protective effects of menstrual blood loss and pregnancies . The clinical signs associate fatigue, arthritis, hepatomegaly, skin pigmentation and diabetes and can progress towards cirrhosis and carcinoma.