I'm 20 years old. I do not have any bad Habits like smoking drinking etc .but I am very nervous not for every time for example: when I see blood flowing from any person I get nervous and I will become unconscious and if I'm fighting with someone at that time I don't have any problem but after fight my hands are shivering .my friend says that you are like this because you do not smoke or drink .is this is true or how I will recover from this.