Will marijuana show up on an ordinary blood test?

Question

Three of my friend's are getting various blood testing done within the next week. One for mono, another for cholesterol and the third is donating blood. Will the doctors immediately know that they've smoked pot in the recent past, or does it not matter?

Answer 1

no they wont know because the test their running are specific. they don't just test for mary jane unless their looking for it. Donating blood they do not test for marijuana