It is not 'just' the one and a quarter million people who have the double genes to develop HH, but it is also the 25 to 35 million who have the single gene or are carriers of HH that we have to deal with. Those with the double genes are the ones who absorb too much iron and those with the single gene absorb more than the normal person. No one knows just how much storage iron or iron overload is necessary to cause disease problems, but rest assured it is not near so much as it was once thought to be. This is a good place to describe why extra iron in the body causes such problems. The main problem is related to free radical pathology.
Iron overload is holistic in that it affects the entire body.
Let's start at the top. Hair loss is caused by iron overload. This in itself is no big deal and may only be embarrassing to the patient, but don't forget this minor problem for the clue to a diagnosis. In those people with H, the brain is involved in that some of the people may have a sense of vertigo and a loss of memory. Evidence is now pointing to Alzheimer's disease, Parkinson's and Tardive Dyskinesia being connected with iron overload.