Patient Evaluation Mnemonics For Your USMLE Prep

  • /Reviewed by: Amy Rontal, MD
  • Dr. Ali Elsaadi and Dr. Taylor Purvis contributed to this post.

    A few questions I often get from students are along the lines of, “what’s the best way to memorize the signs of symptoms of this disease?” or something like, “what’s a quick mnemonic I can rely on for all the adverse effects of this drug?” Now, before I answer this, I must say I have always been a bit wary of using mnemonics (I’m looking at you First Aid and your infamous “Most chronic alcoholics Steal Phen Phen and Never Refuse Greasy Carbs/SICKFACES.COM” nonsense), but things changed for me during dedicated USMLE prep when I realized that, just like everything else in life, you can find a diamond in the rough when it comes to these clever ways of learning content.

    Here are a few USMLE mnemonics and how you can learn from them/use them to your advantage in ruling out incorrect answers in a question stem:

    1. MUDPILES for anion gap acidosis
    2. OPQRST
    4. ABCDE

    Topic: Anion Gap Acidosis

    Mnemonic: MUDPILES 

    Methanol, Uremia, DKA, Propylene glycol, Isoniazid/Iron, Lactic acidosis, Ethylene Glycol, and Salicylates. This is probably one of the most used mnemonics in medicine (GOLDMARK is the equivalent to it with the D standing for D-lactate but that’s not too important for Step 1 just yet), and it has a ton of utility when preparing for your Step 1 as well.

    Now I’m not saying just memorizing what it stands for is good enough, but if you can relate each disease to an underlying principal such as physiology or biochemistry or even principles of management, you’ll be able to kill two birds with one stone.

    Let me give you an example using DKA. This disease gives you an anion gap metabolic acidosis (it’s one of our MUDPILES). But how do you get the acidosis? What lab values are consistent with this acidosis? What’s going on in the kidneys while all this is happening? What about respiratory rate? Can people with type 2 diabetes get this?!!

    All these questions and more are what you should be going through with every single disease in this list. Once you know all that, figuring out how to fix these people is easy. Just correct what’s abnormal and you’ll be smooth sailing (on the exam, they usually die despite your best resuscitation efforts so don’t feel too bad.)

    Topic: Patient History and Pain Evaluation

    Mnemonic: OPQRST

    Onset/Ongoing (when did it start and how long has it been going on), Position (where is it located), Quality/Quantity (what is the character of the pain and how bad is it from 1-10), Radiation (where does it move), Symptoms (associated symptoms), and Transforming factors (what makes it better or worse).

    Most people use this mnemonic whenever they’re taking a history in real life and trying to evaluate pain. Its use doesn’t stop there though.

    Whenever you are reading a question stem, think of this mnemonic whenever your patient has pain. Let me give you an example with aortic dissection. A patient comes in with substernal chest pain of 2hrs duration that is tearing in nature and radiating to the back. The pain doesn’t get worse with inspiration. The patient’s blood pressure is 160/100 in the right arm and 140/80 in the left arm. What’s the most likely diagnosis?

    Hopefully you came to the answer of aortic dissection, but how could you have distinguished this from an MI, PE, or even GERD? This is where OPQRST comes into play. With that simple mnemonic you could have ruled out each one of those choices because of how different the pain. GERD doesn’t radiate for example and is associated with food, MI radiates to the arm usually and is squeezing in nature, while PE has pleuritic pain. Try setting up a list of common causes of pain and evaluating them with OPQRST.

    Topic: Generating Differentials

    Mnemonic: VITAMIN CDE

    Vascular, Infectious/Inflammatory, Traumatic/Toxic, Autoimmune, Metabolic, Idiopathic/Iatrogenic, Neoplastic, Congenital, Degenerative, and Endocrine.

    This mnemonic is the first one I learned in medical school that I actually liked. We used to get cases in lecture and the first thing we would do is read the chief complaint and then generate a differential using VITAMIN CDE. As always, let me give you an example.

    CC: A patient comes in with a swollen, red, and painful joint.

    Vascular issues causing red, swollen, and painful joints are uncommon. Bump it down on your list of differentials.

    Infections (septic arthritis, rheumatic fever), inflammatory (gout, pseudogout)

    Trauma. We don’t know if there was a history of trauma so well keep this in our differential. Toxic. These etiologies tend to be systemic in nature so we can move this down on our differential.

    Autoimmune (reactive arthritis, rheumatoid arthritis, seronegative spondyloarthropathies, SLE).

    Metabolic. These also tend to be more systemic, so we can move this down.

    Idiopathic. On Step 1 the answer is rarely idiopathic but if you’ve ruled everything else out consider this. Iatrogenic. Look for a patient with a recent hospitalization or surgery.

    Neoplastic. Malignancy is always something you want to give at least a little consideration too. There’s so many paraneoplastic syndromes that you never want to rule it out without at least getting the full history.

    Congenital. Usually if you have an older patient you can throw this out the window.

    Degenerative (osteoarthritis)

    Endocrine. These also tend to be more systemic so it’s less likely in this case.

    Once you get the rest of your history, physical, labs, and imaging, you can re-evaluate this list and decide if you want to move up or move down some of your differentials.

    Topic: Chest Radiographs

    Mnemonic: ABCDE

    Does your heart skip a beat when you see a chest radiograph as part of a question stem? Try using a simple mnemonic to organize your interpretation of the image.

    The mnemonic is simple: ABCDE

    A: AP or PA? & Airways

    Is the film an AP film or PA film?

    Start at the top of the image and look at the airway. Follow the trachea to the carina and ask yourself, is it straight? (No: possible tension pneumothorax.) Is there narrowing? (Yes: Tracheal stenosis.) Follow both bronchi: do you see any foreign bodies? (Yes: That’s probably why that kid in the vignette has respiratory symptoms!)

    B: Breathing and Bones

    Now’s the time to look at lungs. Are both lungs the same size? (No: Pneumothorax?) Can you see around 10 posterior ribs? Are the left and right heart borders sharp and clear? Does any lung zone appear more dense than others? Any hilar adenopathy? (Yes: sarcoidosis.)

    Also take a look for any bony pathology. Do this in a systematic fashion: follow each posterior rib, looking for fractures or abnormalities. The clavices, shoulders, and vertebral bodies. For vertebral bodies, do you see disc spaces? (No: ankylosing spondylitis.) Are they all about the same height? (No: vertebral compression fracture.)

    C: Cardiac, Circulation, Costophrenic angles

    This includes the heart and pulmonary vessels. Is the heart in the right place? Is the cardiothoracic ratio <50%? (No: cardiomegaly.) Normal width of upper mediastinum? (No: aortic dissection, anthrax.) Do you see sharp costophrenic angles? (No: Pleural effusion.)

    D: Diaphragm & Digestion

    Diaphragmatic flattening? (Yes: COPD.) Any free air? Any hiatal hernia?

    E: Edges & Everything Else

    Are the edges of the lung normal? (No: pleural plaques or thickening, lung fibrosis, pneumothorax.) Any foreign materials like clips, lines, pacemakers, ICDs, catheters? Any subcutaneous emphysema?


    Mnemonics can really help you on your exam if you utilize them to their fullest. Sometimes, it’s the simple ones that can give you the most information. Look for ones that you can apply to multiple situations and the ones that give you a quick and dirty list from which you can generate questions for yourself to practice that material.

    Remember, don’t just memorize. Try and make everything relatable (except the mnemonics for CYP inducers and inhibitors you really just have to memorize it and hope you get an easy question on it) and trust yourself that you will be able to learn the content you need to in order to get the score you want.