Nerve gas works by blocking the normal functioning of chemicals at nerve endings. This causes the body to go into overload which will cause paralysis and death.
References:
Here's why nerve agents are some of the most deadly chemicals on Earth
https://www.businessinsider.com/sarin...
Health Effects of Nerve Agents 1063
• Health Effects of Nerve Agents 1963
What are Nerve Agents and how do they work?
https://www.scientificamerican.com/ar...