How does a doctor diagnose your illness? (Differential Diagnosis)

Imagine that you've had a bad stomach ache for a few days. So you go to see a doctor. The doctor asks you questions, examines you, and says, "Hmm... it could be gastritis, it could be appendicitis. Let's do some tests." Have you ever wondered why doctors don't just say what the problem is, they just say a few things that could be wrong? That's what we call differential diagnosis in medicine. Don't worry, it's a big word, but it's very simple. Let's talk about it today.

Simply put, what is differential diagnosis?

This is not your final diagnosis. Think of a good detective. When he goes to a crime scene, he doesn't immediately say, "This is the culprit," does he? The first thing he does is make a list of people he suspects may have committed the crime. Then he collects evidence, checks each other, eliminates irrelevant people from that list, and finally catches the real culprit.

A doctor does something similar. When you come in with some symptoms, the doctor comes up with a list of possible diseases that fit those symptoms. That "list of possible diseases" is what we call (Differential Diagnosis). This is a very important first step in the diagnostic process.

What steps does a doctor use to accurately diagnose an illness?

There is a systematic journey that the doctor takes to find out exactly what the illness is. It is like climbing a flight of stairs. You cannot skip a single step.

1. They ask you a lot about your symptoms: "How are you feeling?", "How long have you had this problem?", "What does the pain feel like? Is it stabbing? Or is it like something is pressing?", "What other problems are you having?" They try to get a complete picture of your condition by asking questions like: "How are you feeling?", "How long have you been having this problem

2. Ask about your medical history: "Have you ever had this happen to you before?", "Do you have other illnesses like diabetes or high blood pressure?", "Does anyone in your family have these illnesses?", "Are you taking any medications or vitamins?" All of this is important.

3. Physical Examination: In this, they will touch your body, palpate your abdomen, listen to your chest and lungs with a stethoscope, measure your blood pressure, and check your temperature. These will give the doctor a lot of clues.

4. A list of possible diseases (Differential Diagnosis) is created in the mind: Now, after putting together all the details you have told us and the things that were felt during the examination, the doctor thinks, "Okay, based on these symptoms, this could be this disease."

5. If necessary, more tests will be prescribed: More evidence is needed to find the real culprit from that list of suspects. That's why things like blood tests, urine tests, scans, and X-rays are done.

6. Reviewing Test Results and Symptoms: Once the test results come in, the doctor will compare them with your symptoms. Then, he or she can eliminate some of the diseases on the list by saying, "No, this can't be it."

7. Coming to a Final Diagnosis: After all this is done, the doctor is finally able to say with certainty, "Yes, you have this disease." Only then can the appropriate treatment begin.

Why is it necessary to make a list like this? Is it because it can be wrong?

To be precise, this method is used to prevent mistakes . Imagine, if someone comes in with chest pain, the doctor thinks, "Oh, this is gastritis" and gives them medicine for it, but what if it's actually the beginning of a heart attack? That could be a big accident, right?

But when a doctor uses the Differential Diagnosis method, he thinks, "This chest pain could be due to gastritis. At the same time, it could also be due to a muscle strain. But the most dangerous thing is that there is a small chance that it could be a heart attack." Then he does the necessary tests (e.g., an ECG) to confirm whether or not the most dangerous thing is possible. Once it is confirmed that it is not a heart attack, he can look at other causes. This is to ensure your safety.

Some examples of diseases with similar symptoms

To understand how important this process is, let's look at some common symptoms and the different medical conditions that can cause them.

Now you can see how many different causes there can be for the same symptom, right? So you can see how important it is for your safety for a doctor to think this way.

What needs to happen on your part in this process?

In this detective journey, you are the main witness. Therefore, your help is very valuable to the doctor .

• Be honest about everything: Don't hide even the smallest things you're feeling. Sometimes, something you think "this doesn't really matter" can be a big clue for the doctor to find the problem.
• Bring a list of your medications: Tell your doctor about all the medications you are taking (those for other conditions, vitamins, powders, even Sinhala medicines). Sometimes, the cause of your symptoms may be another medication you are taking.
• Don't be afraid to ask questions: "Doctor, what kind of illness could this be?", "What kind of tests do I need to do?", "What can I expect from these tests?" Ask. The more informed you are, the less afraid you will be.
• Stay calm: Don't be alarmed when a doctor says, "It could be this disease, it could be that disease." Remember, that doesn't mean you have all of those diseases. It just means that they are considering all the possibilities before they can pinpoint the exact disease.

When do you want to see the doctor again?

During the diagnosis process, it is important to inform your doctor if there are any changes in your condition. Be sure to call or see your doctor again in the following situations:

• If your symptoms suddenly worsen or disappear completely.
• If you develop new symptoms.
• If you have to be hospitalized for any other reason.
• If you need to make any changes to the medications you are currently taking (e.g. if a different doctor prescribes a new medication)

This information will help the doctor diagnose your illness.

Differential Diagnosis, Diagnosis, How to diagnose a disease, Symptoms, Medical tests, Doctor