Mechanisms of Disease
To come up with a differential diagnosis, a preferred framework to use is:
1) an Anatomic framework, or
2) a Physiologic framework.
However, I have found that applying a mechanisms-of-disease based approach within the context of an anatomic framework works very well. An example of mechanisms based approach is the mnemonic VINDICATED MEN that gives one the major mechanisms of diseases. It is an upgrade of the popular mnemonic called VINDICATE.
For example, to work up abdominal pain, an anatomic framework works very well. You may split the abdomen into quadrants and identify the organs that live there or are referred there. Using VINDICATED MEN will quickly help to remind you of the possible mechanisms of disease within each specific anatomic region (or organ/system) that you are considering. It is also useful as an accessory device that either stimulates your memory or helps when you cannot think of more reasonable differential diagnosis options using an anatomic or physiologic framework.
VINDICATED MEN covers the different mechanisms of disease. Note that VITAMINS ABCDEK is another rendition of the VINDICATED MEN.
**I have created a new mnemonic called CASE DIAGNOSED! that I think is easy to remember and is more comprehensive.
Differential Diagnosis by Mechanisms of Disease: VINDICATED MEN
Vascular/Vessels (flow)- conduction problems like narrowing, obstruction, and rupture or vessel inflammation, infection, etc. A vessel is a duct, canal, or another tube that contains or conveys a body fluid. E.g. blood vessels (arteries, veins, heart*), lymphatic vessels. The GI tract is a vessel. So is the biliary system. Nerves are also vessels that carry information from one place to another. Good body function depends on things being conducted from one place to another efficiently. When natural “flow” is affected (interrupted, slowed, obstructed, sped up), disease happens. ** Vessel problems could be with the architecture (constitution) or content of the vessel.
Infection + inflammatory (non-infectious) conditions. E.g. IBS.
Neoplasm (primary tumor or metastatic)
Drugs, Diet, and ingestions: This includes drug-induced or drug-withdrawal. Drugs (substances) include both prescription, nonprescription drugs, and illicit drugs. Diet (Food) poisoning, etc. Drugs and food go together as in the FDA (Food and Drug Administration).
Idiopathic. We don’t know.
Congenital. Congenital means a condition is present at birth, whether inherited (genetic) or caused by environmental factors. Congenital malformations go here as well. Note that many congenital issues may not sure up til later. E.g. AVMs are usually congenital. Also, some mild heritable enzyme deficiencies like Gilberts, etc.
Autoimmune & Allergic. See the list of autoimmune diseases. Note that autoimmune diseases have manifestations in different organ systems.
Trauma and treatment s/e (iatrogenic causes)
Endocrine/Metabolic causes (disorders of homeostasis)
Deficiencies and excesses
Musculoskeletal disorders
Environmental exposure. E.g. excessive exposure to sun, heat, cold, freezing temperatures. Carbon monoxide poisoning, lead poisoning, something in the water, etc.
Neuropsychiatric disorders (neurologic and psychiatric disorders)
The categories are not meant to be exclusive but comprehensive when treated together.
Degenerative diseases fall under musculoskeletal.
You can make the C in congenital to stand for Cancer and the N in Neoplasm to be something like Newborn disorder / Newborn Screening
Inheritance/genetics is a mechanism of disease and many of the congenital disorders are heritable.
The heart as a vessel
*”The heart is a specialized blood vessel designed to pump blood. Embryologically, the heart begins as two tubes that fuse and becomes subdivided into four chambers.” ice.uthscsa.edu
The GI Tract as a vessel
Envision the gastrointestinal tract as a vessel which carries things from the mouth to the anus and within which digestive forces convert nutrients into energy for absorption and assimilation.
The biliary system is also a system of vessels.
The GI as a vessel is supplied with other vessels that carry blood, lymph, nerve signals to support the function of the bigger GI vessel. When natural flow is affected in any of these vessels, disease happens.
Further Reading
Zabidi-Hussin ZA. Practical way of creating differential diagnoses through an expanded VITAMINSABCDEK mnemonic. Adv Med Educ Pract. 2016;7:247–248. Published 2016 Apr 22. doi:10.2147/AMEP.S106507
https://www.ncbi.nlm.nih.gov/books/NBK379263/