The overreaction of your immune system to a substance that is, in and of itself, harmless, such as pollen, is what causes allergies. During such a reaction, your immune response sends a signal to your cells to release a substance ...
The overreaction of your immune system to a substance that is, in and of itself, harmless, such as pollen, is what causes allergies. During such a reaction, your immune response sends a signal to your cells to release a substance ...