I woke up this morning and now i can't smell. what is this?

Infammation smells : Nasal inflammation can cause anosmia (loss of sense of smell). Since most of taste is related to smell they often are both affected. An unlikely cause is a tumor. Although medications can usual decrease nasal symptoms due to infammation anosmia may persist. Oral or injectable steroids often temporarily restore taste and smell, but side effect Prohibit their use.