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.
How Gas Can Cause Anxiety. No matter what causes your gas, gas itself can actually lead to further anxiety. Overwhelming gas can cause both stomach pains and chest pains, and - depending on where you are - you may experience additional anxiety by trying not to pass that gas in public.