When Laura Jackson first began to experience bouts of tiredness, she put it down to being a working mum with two babies.

Then 38, Laura had a one-year-old and a three-year-old who she says kept her up most nights.

But things changed when, last year, she went to give blood.

Laura has a rare type of blood – A-negative – and regularly donates.

So she was surprised when she was told she was not allowed to on this occasion. Her blood, the nurse explained, was markedly low in iron.