High voltage applied to a low voltage range may destroy the meter - and also may destroy you.
Low voltage applied to a high voltage range will not damage the meter, or you.
High current applied to a low current range may destroy the meter - and also may destroy you.
Low current applied to a high current range will not damage the meter, or you.
Added:
Note this stack exchange question which was asked about 15 hours after this one.
This is the voltage across the leads when in that mode. Since the open voltage in diode check mode is only 1.48V, it is unlikely that a LED with a forward voltage much higher than that (usually at least 2.2V) will test properly.
Best Answer
Diodes have a small leakage current when reverse biased and that is the current you will measure - leakage current: -