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.
Phosgene would be responsible for more than three-quarters of the gas fatalities during World War I. A British soldier affected by mustard gas burns. The most notorious chemical weapon of the war was mustard gas, a severe irritant which caused chemical burns on the skin, the eyes and in the airways. Though not as deadly as other compounds, mustard gas probably had more effect as an anti-personnel weapon.