Your handwriting can reveal many things about you that you are probably unaware. The science of handwriting analysis has progressed significantly. Practitioners of analytical techniques offer their services at a price, so the science has grown up from a past time to a full fledged approach to seeing within human personality. The fact is that everything that we do can be analysed forensically. The results may not be accurate or they may hit spot on in ways that get to the deeper sources of illness and physical conditions as well as personality traits. One has to be careful with claims that handwriting analysis is all powerful. It is still a very young science.I remember my father, a minister of religion, who visited the sick in a local insane assylum telling me in the 1960's that handwriting analysis was being used to understand mental illness. He said that they were experimenting with a therapy to reach the deeper parts of the brain by training 'mentally ill' people how to improve their handwriting. Apparently, just the training in handwriting arts could result in more organized thought and behaviour at very deep psychological levels.
A french Canadian student of psychology who I worked with in a summer job at Weston's Bakery in Longueuil, Quebec who would tease me that every motion I made could be analysed by a trained psychologist and that I was forever giving off clues about my weaknesses that a trained person could understand and use to recommend therapy, i.e. that I was strange and need help.
Your handwriting does let others know whether you are under stress or likely to be ill.