Dear *****nah In Sydney,
Women are generally blessed with a more acute and sensitive olfactory ability than men, which actually peaks in the 30's.
The effect of brain tumors occurs in 2 ways. First, a type of tumor that grows on top of the olfactory nerve can result in the loss of the ability to smell.
Second, a tumor in the temporal lobe can cause seizures, whose aura or warning is a (usually) noxious odor.
In short, you should be reassured that your sensitivity to odor is more normal than not, and almost certainly not a sign of a brain tumor.
I hope that helps you.
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