You have not mentioned your age. are you addicted to alchocol and smoking? Is vast Networking is your profession?
Consumption of alchocol regulary will affect Central Nervuos System. Regular smoking will affect the fuction of heart. Everybody knows this. Knowingly they are abusing their body.
If you are in a job involving exposure to vast net working take 10 to 15 minutes away from Compter.
For nervous system you must consult a good Doctor and take his advice.
Have a nice and good day.