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.
Citation: C N Trueman Gas masks in World War One. historylearningsite.co.uk. The History Learning Site, 31 Mar 2015. 16 Aug 2016. Gas masks used in World War One were made as a result of poison gas attacks that took the Allies in the trenches on the Western Front by surprise. Early gas masks were crude as would be expected as no-one had thought that poison gas would ever be used in warfare as the mere thought seemed too shocking.