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.
During World War 1, chlorine and other deadly gasses were dispersed onto battlefields to kill or incapacitate unprotected soldiers. As a war gas, it acts by blistering the sensitive membranes of the eyes, nose and lungs, blinding the victim and causing the lungs to ooze fluid into the lungs. In effect, the victim drowns in his own fluids.