A change to your nail could be a warning sign of several health issues, including fluid on the lung and cancer. Whilst many of us pay little attention to our nails , their appearance can often provide 'clues' to our health. Dr Amir Khan, who you may recognise from his regular appearance on ITV's Lorraine, says our nails should feel 'smooth' and have a 'consistent colour all the way through'. Of course, it is perfectly normal to have the odd spot of colour if, for example, you end up hurting