Picture shows swelling to the feet of Laura Pell, 34, from Northampton. Laura was struck by a mystery illness causing her to gain eight stone in six months. January 8 2015. A pretty make-up artist told yesterday (Thurs) how she had become a "human waterbed" after a mystery illness caused her to balloon to almost twice her size - in just six months. See NTI story NTISWELL. Petite Laura Pell, 34, weighed nine stone (57kg) last summer and kept herself in shape by going to gym three times a week and eating a sensible diet. But after being struck down with a mystery illness which has baffled doctors, she began to retain fluid which caused her body to swell in size. She piled on more than a stone in weight in just 24 hours and now tips the scales at 17 stone - and is putting on an average of one-a-half-stone every month. Laura, who lives with boyfriend Mark Appleby, 30, in Kingsthorpe, Northants., has also been forced to splash out on a completely new set of clothes after going from a trim size 10 to a bulky size 22 since last July. The once striking brunette has also been forced to give up her job as a wedding make-up artist because she struggles to walk and fears she will end up in a wheelchair if a cure is not found.