Internal medicine specialists, also known as general internal medicine specialists or general medicine physicians in Commonwealth countries,[10] are specialist physicians trained to manage particularly complex or multisystem disease conditions that single-organ-disease specialists may not be trained to deal with.[11] They may be asked to tackle undifferentiated presentations that cannot be easily fitted within the expertise of a single-organ specialty,[12] such as dyspnoea, fatigue, weight loss, chest pain, confusion or change in conscious state.[13] They may manage serious acute illnesses that affect multiple organ systems at the same time in a single patient, and they may manage multiple chronic diseases or "comorbidities" that a single patient may have.[14]