As mentioned, when a vasovagal reaction is about to begin, you can often recognize the warning signs. So there is usually time to take action before you faint.
तुमच्या मेंदूला ऑक्सीजनचे जे प्रमाण मिळाले पाहिजे ते मिळत नाही आणि तुम्ही बेशुद्ध पडता.