As you asked so nicely Wiggy !!!!
The tests and measurements in the medical wont demonstrate if you are feeling off colour but my doctor certainly looks in my throat which I suspect would have been a give away and the OP suggest he told the doctor who was 'indifferent'.
If I were the doctor and the candidate was desperate not to postpone the medical (license about to expire, upcoming rostas...) I would go ahead but stop if a test was failed where the failure was likely (almost certainly!!!) due to the temporary illness. Normally we commiserate and offer a new appointment