Let me summarize some precautions before donating blood for everyone, so as not to make a trip in vain.
Precautions before blood donation:
At least 18 years old;
Men weigh more than 50KG and women weigh more than 45KG; ;
No cold and acute gastroenteritis within a week, no medication;
Not drinking alcohol within 24 hours;
Didn't stay up late the night before;
Don't eat on an empty stomach, eat lightly before donating blood and don't eat greasy food;
Women are not during menstruation and three days before and after menstruation;
Bring your ID card.