Whats the difference between vaginal discharge and yeast infection discharge? Could a std cause a yeast infection?

STD vs yeast. No STD causes yeast infections. Usually vaginal yeast infections cause no discharge, or only a slight amount, usually white and thick. The main symptoms of yeast are itching, irritation, and sometimes redness of the labia, vaginal opening, etc. There are many causes of vaginal discharge, including STDs. Since you ask about STDs, probably you suspect you may be at risk, so get tested. Good luck!