The amount of time needed for iron to increase to levels causing organ damage is variable and may be partially dependent on gender, dietary or other environmental factors, and unknown genetic factors.
Blood loss through menstruation and pregnancy are thought to delay the onset of iron overload, and therefore symptoms of HH, in women. Similarly, regular blood donation may confer some degree of protection. The loss of hemoglobin within intact erythrocytes reduces the amount of iron available for recycling.
As levels of storage iron increase, clinical features of iron overload, including hepatic dysfunction or failure, diabetes, hypogonadism, arthritis, cardiomyopathy, hyperpigmentation, and fatigue may become evident.
Symptoms usually occur between the ages of 30 and 60, although this is quite variable. Persons as young as 20 may show clinical signs and symptoms of HH.(6) In the US, males are more than twice as likely as females to be diagnosed with HH, and the majority of cases are found in Caucasians. Prevalence of HH is much lower in other racial/ethnic groups, including Native Americans, Hispanics, Blacks, and Asians.