Hazy mental states, such as FOG, are a type of cognitive impairment that can be caused by a variety of factors, including physical or psychological illness, substance abuse, or fatigue. The term 'FOG' is often used to describe this state of confusion and disorientation, which can lead to difficulty concentrating, memory problems, and difficulty making decisions. FOG is an example of a hazy mental state, which can also include other forms of mental confusion, such as delirium, dementia, and psychosis.