Diagnostic Schema


A diagnostic schema is a cognitive tool that allows clinicians to systematically approach a clinical problem by providing an organizing scaffold. 

For example, a commonly used schema for acute kidney injury (AKI) separates this problem into pre-renal, intrinsic, and post-renal causes. By approaching AKI using these categories, clinicians can systematically access and explore individual illness scripts as potential diagnoses.

  • Because they can be retrieved and manipulated as a single item within the working memory, schema also help clinicians to manage their cognitive load and maintain the bandwidth for effective problem-solving.

Examples of Basic Diagnostic Schema

Bilateral lower extremity edema

1. Cardiac
2. Liver
3. Renal
4. Vascular
5. Lymphatic


1. Blood Loss
2. Decreased Production
3. Increased Destruction

Intrinsic Renal Injury in AKI

1. Glomerular
2. Tubular
3. Interstitial
4. Vascular

Benefits of Diagnostic Schema

Tether diagnostic thinking to a logical framework

A logical framework (e.g. structural/anatomic, physiologic, systems-based) is more easily remembered.

Avoid missing diagnoses

A diagnostic schema helps clinicians avoid leaving off categories of illnesses, or anchoring on the most familiar diagnoses.

Trigger search for differentiating features

Diagnostic schema can help trigger clinicians to perform differentiating historical or physical exam maneuvers to refine the differential diagnosis. (e.g. the schema for volume overload triggers the clinician to check the jugular venous pressure as that will help to differentiate among the potential diagnostic categories for this problem)

Teach others how to reason

A schema is easily an efficient way to teach others how to approach a clinical problem ("think aloud").

Creating Diagnostic Schema

Through deliberate practice, learners adapt and individualize their schema — tying these frameworks to prior clinical knowledge and experience, which keeps them robust and accessible. Over time individuals may find that collapsing certain categories, or creating new ones, allows a schema to “work” best for them.

Finding Schemas