Smelling burnt toast can be a sign of a medical condition, but it can also be a type of phantom smell called phantosmia. Phantosmia is a condition that causes you to smell things that aren’t there, and it can be caused by problems with the nose or nasal cavity, or problems with how the brain understands smells. Smelling burnt toast in particular is a common type of phantosmia, but it is not diagnostic. While smelling something that isn’t there is not necessarily a medical emergency, it can be a sign of a more serious condition, so it is important to see a doctor if you experience this symptom. If you have specific signs of a serious condition, such as a recent head injury, a seizure or history of seizures, fatigue, unexplained weight loss, memory issues, tremors, or gait issues, you should see a doctor as soon as possible.