New to Diagnosis123?


You’re sick, and want someone to do something. But Clinicians / Medical Providers (nurse practitioners, doctors, physician assistants, etc.) can’t truly help much unless we know what’s wrong. We need a Diagnosis — our Diagnosis123 website shows how we think it through.

Our starting point is always your Main Symptom.

Pick from our Symptom List. You might then be asked to narrow it down, for example:

HEADACHE โ†’ “Acute” (<3-4 wks); OR “Recurrent” (comes, goes away, happens again); OR “Chronic” (>1 month)

CHEST PAIN โ†’ “Pleuritic” (hurts with each breath); OR “Non-Pleuritic” (steady pain, unaffected by breathing)


Then you’ll see a SUMMARY for each symptom, usually with a list of many possible causes. You’ll find key criteria, which lead us Clinicians to either favor that diagnosis, or rule it out (discard it as unlikely). If you’re really interested in a symptom, there’ll be links to long texts explaining the thought process in lots more depth (I mean it).

Summaries may sometimes include “Red Flags” (danger signs), that might prompt us to simply send a patient to the emergency room (ER). Both the Summaries and texts contain links describing a variety of concepts, tests, great stories, etc.

If a disease stokes you, click its link for a nutshell description of how it usually evolves & plays out. You’ll also learn about the more complex tests that get used to diagnose it. The overall perspective is that of an out-patient clinician in an office, clinic, urgent care setting, or even an ER (not the in-patient provider for those admitted to a hospital).

To better understand this website’s goals (& so you don’t sue us), please take a look at our Introduction, with its Disclaimer. You might also be interested in an overall outline of our Diagnostic Thought Process.

No offense to A.I. enthusiasts (artificial intelligence), but the author of this site doesn’t believe you can click a bunch of options & find out what’s wrong. You have to think it through yourself, like we Clinicians do. Is that possible? Haven’t doctors gone through so many years of schooling to learn everything there is. Well, even if they’ve studied a lot, nobody remembers it all during the 15 minutes we see a patient (far from it). We Clinicians use shortcut all the time.

Diagnosis123 teaches you those shortcuts, i.e. our basic thought process.

Do Enjoy!

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