Terminal illness is a term used to describe an illness which cannot be cured and will almost definitely end in the death of the patient. The term is mostly used for progressive diseases such as cancer or advanced heart disease. Someone who has a terminal illness may be described as a terminal patient or as being terminally ill. Usually a patient is called "terminally ill" when they are not expected to live more than 6 months. Medical conditions such as AIDS are not called terminal illnesses because the patient may live for many years before eventually dying of the illness.