A lot of times, disadvantages of something are mentioned which are precautions in reality. How can we draw that sensitive line between disadvantages and precautions?
A precaution is a measure taken to ensure that a disadvantage does not materialize. So foreknowledge of possible disadvantages leads to precautions and not the other way around.
A corollary to Kirk MacGregor's answer: nevertheless some precautions are disadvantages that one accepts in order to avoid or mitigate greater disadvantages. (Every insurance policy incurs a premium.)