Bruising and Bleeding. Bruising or bleeding after an injury is normal. However, some people have disorders that cause them to bruise or bleed too easily. Sometimes people bleed without any obvious triggering event or injury.
The skin of victims of mustard gas blistered, the eyes became very sore and they began to vomit. Mustard gas caused internal and external bleeding and attacked the bronchial tubes, stripping off the mucous membrane. This was extremely painful and most soldiers had to be strapped to their beds.
Mustard agent was first used as a CW agent during the latter part of the First World War and caused lung and eye injuries to a very large number of soldiers. Many of them still suffered pain 30-40 years after they had been exposed, mainly as a result of injuries to the eyes and chronic respiratory disorders.