Difference between Prognosis and Diagnosis

Key Difference: In medical terms, prognosis refers to a forecasting or prediction about the likely outcome or course of a disease. It may also refer to the prediction related to the likelihood of recovery from a disease. On the other hand, diagnosis refers to the identification and recognition of a possible disease or disorder.

Diagnosis is an important term which is frequently used in medical field. It refers to the identification of a disease or a disorder. The symptoms are used to identify the disease or disorder. Differential diagnosis is also a systematic method in which disorders are identified without having any related unique symptoms or signs.

The word diagnosis has been derived from the Greek, where it meant specifically a ‘discrimination or a distinguishing, or a discerning between two possibilities’. The process of diagnosis ends by reaching to an opinion known as diagnostic opinion. An accurate diagnosis always help in ensuring the best possible treatment, therefore it is taken very seriously. An early diagnosis also prepares a person to get prepared financially, legally, etc. for the treatment.

In medical terms, prognosis refers to a forecasting or prediction about the likely outcome or course of a disease. It may also refer to the prediction related to the likelihood of recovery from a disease. The word has been derived from Greek word πρόγνωσι meaning "fore-knowing, foreseeing". It is commonly used for predicting the chances of recovery or survival from any disease.

The physicians provide prognosis by researching on the statistics based on the behavior of a particular disease in a general population. Prognosis differs from one disease to the other. It also depends on many different types of factors. The same disease may have different prognosis based on attributes like stages of disease at diagnosis, types of disease, and even gender. When a person is diagnosed with any severe disease, the person wants to know that it can be treated successfully or not.

This particular aspect describes prognosis to define the likely course, outcome of the disease and also the chances of recovery. Doctors often make use of survival statistics to make the predictions about prognosis. Diagnosis is all about identifying the illness, whereas prognosis is all about the predictions related to the outcome and the future for the patient.

Comparison between Prognosis and Diagnosis:

	Prognosis	Diagnosis
Definition	In medical terms, prognosis refers to a forecasting or prediction about the likely outcome or course of a disease. It may also refer to the prediction related to the likelihood of recovery from a disease.	It refers to the identification of a disease or a disorder. The symptoms are used to identify the disease or disorder.
Process	Expectations from a certain treatment are drawn according to the factors like doctors’ understanding of that particular medical condition, age, etc. The doctor predicts that how the patient will progress over time.	The symptoms and signs are analyzed and then the investigation is done in order to reach the results. It is basically the name of the disease or disorder.
Word	"Pro-" meaning forward	"Dia-" meaning through or across
Condition	Anticipated progression of the diagnosed condition	Places a name or label on a person’s medical condition
Example	Statistics related to cancer specific survival, relative survival and overall survival may be used for estimating a cancer patients’ prognosis.	Actual diagnosis of prostate cancer is done by a prostate biopsy.
Word Origin	Greek πρόγνωσις "fore-knowing, foreseeing"	Greek, from diagignōskein 'distinguish, discern'