London - When tiredness is a sign of too much iron in your blood.
Tiredness is usually associated with anaemia, triggered by too little iron in the blood.
However, exhaustion can also be caused by too much iron, linked to the genetic condition haemochromatosis.
This affects around one in 200 people, and leads to the intestine absorbing excess iron from food.
Iron helps carry oxygen around the body. Most people absorb around 1-2mg each day from food, but haemochromatosis sufferers absorb up to four times that amount. Over time it accumulates, so by middle age the body may contain 20g of iron (compared with a typical 4g).
The condition is diagnosed through blood tests.
As well as lethargy, haemochromatosis can lead to joint pain and cirrhosis or scarring of the liver (due to iron build-up).
It is treated with venesection, where blood is regularly removed from the body, like giving blood.
This stimulates bone marrow to make new blood cells and thereby remove excess iron. - Daily Mail