shaskai,on my own experience and on the experience of other people here I can say that often thet difference is caused by edemas. it happens more often on feet/ankles, but sometimes might also happen on hands. Before BFS I had a trouble with my hands - my right one was tingling and numb and also a bit swollen. So it might be that your left hand is just a bit swollen while right hand is as it is. it happens sometimes due to lymphostasis, bad circulation etc. Lower limbs edemas of some specific type are by the way common in people with thyroid troubles (however I am not sure if they also have a hand edemas... who knows.. they have fascial ones for sure, very typical, so maybe upper limbs might be affected too).Atrophy usually indicates also quite a prominent weak muscles.check that remembering anybody who was wearing a cast for a time. Usually one month in a cast is enough for muscles to be a bit atrophied due to non-usage. people with broken leg HAVE TO USE A CANE. People with broken hand have to learn again how to hold a cup - because their muscles are just a bit temporarily atrophied. The CAN NOT HOLD A CUP! While physically the hand or leg might be even not so slim and bony.Should you be really atrophied due to MND, you might be having significant and non-transient difficulties to type, hold utensils etc. If that is not a case - the you are OK and are either super aware of body differences or have a bit of edema on your left hand.