Black marks

A blackened nail is usually caused by blood staining the underside of the nail following a trauma such as stubbing your toe or even wearing tight shoes, says Emma. ‘The stain will grow out with the nail, which takes six to 12 months. Taking a photo of the nail can help you monitor its progress. A black mark that does not grow out could be caused by a skin lesion such as a melanoma – so it must be checked by your podiatrist or GP.’