Difference Between Diagnosis and Prognosis (With Table)

Medical examinations are something we all need to get done from time to time. There are a number of procedures which go in this process, both formal ones, and medical ones. The formal ones are those such as getting an appointment, billing, etc.

The ones related to medicine are diagnosis and prognosis. Usually, people get confused between these two terms. And most people are familiar with the more widely used widely diagnosis, however, there are some people who are aware of what prognosis means.  but it is important to know the difference between the meanings of these two terms.

Diagnosis vs Prognosis

The main difference between diagnosis and prognosis is that diagnosis is the identification of the disease why prognosis is the action taken to recover from the disease.

Diagnosis is the process where the doctor or medical practitioner tries to identify the disease a person is suffering from based on the Science and symptoms he or she is displaying. Diagnosis is the first process that is followed when one visits a doctor, which is then followed by prognosis.

Prognosis is where the doctor or medical practitioner tells the patient the process which has to be followed which will help the patient to recover. it includes which medicine to take and when to take it, what diet has to be followed, what lifestyle changes have to be made, etc.

Difference Between Diagnosis and Prognosis

Parameters of Comparison Diagnosis Prognosis
Definition Diagnosis is the process of identification of the disease by taking into account the signs and symptoms a patient is suffering from. Prognosis is the process that tells us the path which has to be followed in order to recover from the disease that has been diagnosed.
Order Diagnosis is performed first. Prognosis is performed after diagnosis.
Duration Diagnosis usually does not take much time. Prognosis can be long and in some cases might last for years.
Dependency on Age Diagnosis usually does not depend on age. Prognosis depends on age.
Uniqueness Diagnosis is usually the same for everybody hence it is unique. Prognosis usually varies from person to personhence it is not unique.

What is Diagnosis?

Diagnosis is the process of identification of a disease that a patient is suffering from taking into account the signs and symptoms that have been displayed.  diagnosis is usually the first step that is taken when a person sees a doctor order medical practitioner.

Diagnosis should only be performed by a licensed, qualified, and certified person. Diagnosis is a very important step as it is the key step towards recovery. In case of a wrong diagnosis, the whole process of recovery might be misled which may lead to the patient being in a worse condition than he or she is currently in. Hence diagnosis is clearly a very important step.

When a person is diagnosed by a doctor,  the first step in this process is to collect the medical history of the patient to see whether the person has any history with that disease or not. The doctor might also check if the person’s family has any such history with that specific disease as diseases are often passed on by genes.

Then the doctor might have a few specific diseases in mind which the person might be suffering from. This is answered by asking the patient several questions about his or her well being, and how he or she is feeling.  the doctor might also take the help of various tests,  such as a blood test,  x-ray, stool and urine test, etc. This helps the doctor to confirm which disease the patient might be suffering from. Once the disease is pinpointed the process of diagnosis is usually over.

Sometimes a wrong diagnosis might have been performed too,  which might lead to greater problems,  which is why the doctor needs to be very careful and take into account all factors while diagnosing the disease a patient is suffering from.

What is Prognosis?

Prognosis is the step where the recovery part of a patient is decided after diagnosis has been performed and the disease has been identified. Prognosis is usually longer than a diagnosis and in many cases might last for years, or even a lifetime. Prognosis also tells us how the disease is likely to behave in the future, and when it is likely to end. The prognosis might also bring about various lifestyle changes and also changes in things such as diet, exercise, work, etc.

One very important thing about prognosis is that prognosis varies from person to person. Prognosis depends on a number of factors, such as gender, age, pre-existing health conditions, and in some cases, even the country in which one lives.

In most cases prognosis also tells us whether the person will or will not be able to perform any specific activity throughout their lifetime. In a way, prognosis determines how a person’s life will be changed because of the disease they are suffering from.

Prognosis also depends on the disease a person is suffering from, the mental well-being of the patient, and whether the patient is suffering from any other disease. The last point is important because often it can so happen that when a person is suffering from multiple diseases,  the prognosis of one disease interferes with the progress of the other disease,  and thus making things worse.

Prognosis can also change with time as a person gradually heals, are the person’s condition gradually worsens. This should be done under the supervision and guidance of a trained medical expert only.

Main Differences Between Diagnosis and Prognosis

  1. Diagnosis is the process of identification of the disease while prognosis is the process that tells us how to cope and battle with the disease.
  2. Diagnosis is performed first followed by prognosis.
  3. Diagnosis usually does not take much time, but prognosis can even last for a lifetime.
  4. Diagnosis usually does not depend on age, why prognosis depends on age.
  5. The diagnosis of What disease is the same for all people hence it is unique whereas prognosis might vary from person to person hence is not unique.


Being familiar with all these medical terms is important even for a common person of non-medical background. this is because dealing with diseases can be a matter of life and death and being unaware of such terms might sometimes lead to disastrous consequences. It is advisable for everybody to be well-informed, and aware of everything that happens during the process of diagnosis and prognosis. Getting treated by a certified medical expert is always recommended.


  1. https://pdfs.semanticscholar.org/25bf/0126f8a09f04bc55d9d93b1acf2faa1fb49a.pdf
  2. https://journals.sagepub.com/doi/abs/10.1177/0272989×8300300403