From a medical perspective, mental confusion is a state where a person has a limited capacity to understand the world around him or decipher basic facts about reality. This might include mild things like not knowing the date or time, and it could also include more severe things, such as a situation where someone doesn't know his own name. Sometimes people suffering with mental confusion might even have delusions about exactly what is happening to them. For example, a person might misidentify one of his friends as another individual. Many disorders as well as injuries and certain drugs can cause mental confusion.
When many people think about confusion, they might consider the mild mental state where someone doesn't understand something they're being told. Usually, this sort of mild day-to-day confusion isn't of any interest to doctors. It has some similarities to the more medically-serious version of confusion, but it rarely represents a danger, although it can also be a warning sign of the beginnings of something more dangerous. It may be worth taking it seriously if it is particularly severe and the person has any risk factor for mental disorders.
There are a wide variety of different causes for mental confusion, and some of them can be potentially dangerous. For example, confusion is one of the main symptoms of certain brain cancers, as well as Alzheimer's disease. Fevers can also cause confusion, and sometimes they can be severe. If someone becomes confused while suffering with a fever, it could be a sign that the fever is reaching a point of serious concern.
Other causes of confusion can often be much more temporary and might have more to do with outside influences than any disease. For example, many drugs, including those taken for legitimate medical purposes as well as those taken for recreational reasons can cause varying levels of confusion. In fact, alcohol, which is legal in most places, can lead to a severe confused state if it is taken in too great a quantity. Other causes of confusion include head injuries and anything that might lead to a general decrease in the blood flow to the brain.
Mental confusion is usually considered sufficiently disquieting to warrant a visit to the doctor or emergency room. This is especially true when the confusion has no understandable cause, but it can also be a cause for concern even in cases where the source is understood. For example, if someone has been consuming alcohol or is suffering with a fever, if the person has reached a stage where he has trouble understanding things or remembering, it might be a sign that his condition has crossed a line into dangerous territory.
