Macropsia is a neurological condition that causes an altered perception in which objects appear larger than they actually are. This is sometimes referred to as 'Alice in Wonderland syndrome.' It can be a symptom of epileptic disorders, migraines, brain injury or tumors, damage from strokes, mononucleosis, or hallucinogenic drug use. Macropsia doesn't affect the appearance of ALL objects - typically only some objects' size will be distorted.
For example, a small sofa may appear to be the size of a large vehicle. This condition is the opposite of micropsia which is when objects appear to be smaller than they actually are.