What is the difference between a disease and an illness?

Disease and illness are often used interchangeably, but there is actually a subtle difference between the two terms.

Disease is a medical condition that is characterized by a departure from normal body function. Diseases are often caused by factors such as genetics, infection, or environmental toxins.

Illness, on the other hand, is a state of being unwell or unhealthy. Illnesses can be caused by a variety of factors, including diseases, injuries, or mental health conditions.

In general, diseases are more objective than illnesses. This is because diseases can be diagnosed based on specific signs and symptoms. Illnesses, on the other hand, can be more subjective, as they are often based on how a person feels.

For example, a person may have a disease such as diabetes without feeling any symptoms. However, if that person's blood sugar levels become too high, they may experience symptoms such as fatigue, thirst, and blurred vision. At this point, the person would be considered to be ill.

It is important to note that diseases and illnesses are not always mutually exclusive. A person may have a disease that causes no symptoms, or they may have an illness that is not caused by a disease.