Definition: Anosmia, also known as a anosencephalic disorder, refers to an inability or difficulty in olfaction (the sense of smell). It's caused by brain damage that affects the olfactory bulb or the area responsible for sense of smell. Specific symptoms include difficulty or no sense of smell, which can lead to nosebleeds, allergic reactions, and even unconsciousness. Anosmia is a significant issue that requires medical attention. The exact cause of anosmia is not completely understood, but it's thought to be caused by damage in the olfactory bulb or the area responsible for sense of smell. This condition affects around 1-4% of the world's population and can affect different aspects of daily life.