10 free AEMT practice questions: Differential Diagnosis Basics

Narrow the list to one cause before starting treatment: Narrowing to one cause first feels like the disciplined version of this, and it is how students are taught to answer a test question. Resolving a differential takes imaging and laboratory work you do not have. Waiting for that certainty leaves the time-sensitive causes untreated while you look for it.

Choose the most common cause and treat only that one: Playing the odds is exactly what a differential exists to prevent. The common cause usually is the right one, which is what makes the habit so durable and so dangerous. Missing a lethal cause and over-treating a benign one do not cost the same thing.

Report the most likely cause to the hospital as the finding: A single clean cause is what makes a radio report sound crisp, and students hand over their best guess because they want to be useful to the receiving team. Naming one cause turns your working list into a conclusion you are not licensed to draw. The hospital can repeat your examination, and what it cannot rebuild is the list you were holding and why, so communicate the differential rather than the winner.

A seizure with a postictal period: Tongue biting along the side, incontinence, and a witness describing rhythmic shaking are the findings that favor a seizure, and none of them are here. Students pick it because any collapse with confusion afterward reads as postictal to them. Thirty seconds is far too fast for a postictal period.

A stroke with resolving symptoms: A stroke whose symptoms resolve is a real event and a real reason to transport, so students who think of it are thinking well. A stroke produces focal findings, and this patient had no weakness and no speech change at any point.

An episode of low blood glucose: A low blood glucose level does cause collapse and confusion, and it belongs on the list until it is measured. What it does not do is correct itself within 30 seconds without treatment, so the speed of the recovery argues against it.

Acute pulmonary edema, since rhonchi mean fluid has reached the alveoli: The conclusion is right and the reasoning is backwards, which is the version that costs you on an exam. Rhonchi come from secretions in the large airways. Crackles are what fluid in the alveoli sounds like.

An exacerbation of the lung disease, since the patient has carried it for years: A documented history is real information and it is tempting to let it decide the call, especially when the patient has been through this before. A history tells you what is on the list, not which item on the list is active right now, and tonight the sound and the clock both point the other way.

An exacerbation of the lung disease, since crackles are its expected sound: Both diseases put an older patient in severe distress sitting bolt upright, so reaching for the familiar one is understandable. Crackles are not the sound of that disease. Its sound is rhonchi, coarse and low pitched, and often clearing after a cough.

Neither can be chosen until lung sounds have been heard in all fields and compared: Lung sounds do confirm the sorting when neck veins and history agree, so wanting them is sound practice. Waiting on them here delays a decision the mechanism has already made, and a rigid abdomen after an ejection is not an ambiguous story.

Cardiogenic, since distended neck veins mean the pump has failed: Distended neck veins really are the classic sign of a pump that cannot move blood forward, and reaching for that is a reasonable reflex. Veins seen inside a cervical collar in a patient ejected at highway speed are being read through a confounder, and the mechanism outranks them.

Cardiogenic, since cool sweaty skin and a weak fast pulse point there: Cool, sweaty skin and a weak fast pulse are correct observations, and they feel decisive. Both categories produce exactly that picture because both trigger the same compensation, so those findings cannot pick between them.

Whether the patient fell from a standing position: Position at the moment of collapse is worth documenting, and collapsing from standing does fit a faint. Both conditions can drop a standing patient, so the detail narrows nothing on its own.

Whether the skin was pale at the moment of the collapse: Pallor is a real feature of a faint and a witness who noticed it gave you something useful. It is a soft feature reported second hand, and it does not settle the call the way a timed recovery does.

Whether the patient was briefly confused after the collapse: Confusion right after the collapse is the finding everyone notices first, and it is genuinely abnormal. Both conditions produce it, so it cannot separate them. The length of the confusion can.

Whether the respiratory rate has passed 24 breaths in a minute: A rate of 34 is abnormal and deserves attention, so the number pulls at you. Both conditions push the rate well past 24, so a threshold cannot separate them.

Whether the patient can speak in full sentences between breaths: Speech in full sentences is a good general measure of work of breathing and it is quick to check. Both of these patients can usually still get a sentence out, so it does not pick between them.

Whether an emotional trigger can be identified on scene: An argument is right there in front of you and it makes the anxiety story feel complete. A trigger tilts the impression without settling it, and a patient can be upset and acidotic at the same time.

Treat for shock and take no further pressures before arrival: Treating the patient rather than the number is the correct instinct and half of this option is right. Abandoning further pressures throws away the trend, and the trend on a chest pain patient is what tells you whether the plan is tracking the patient.

Accept it, since a measured value outranks an impression: Objective numbers do carry more weight than impressions in general, and that instinct serves you well most of the time. This number came from a poor technique and it contradicts everything else, which is precisely the situation the repeat rule was written for.

Document it and recheck at the routine fifteen minute interval: Fifteen minutes is the right interval for a stable patient and following the schedule is good discipline. This patient is not stable by appearance, and a disagreeing number gets repeated now rather than waiting for the clock.

The dispatch text, since it is the first information received: The dispatch text arrives first and it does shape what you expect to walk into. It comes from a caller who may not have seen the patient, which makes it a hypothesis generator rather than evidence.

The patient, since the patient reports feeling only a little warm: What the patient reports is always worth hearing and it belongs in the narrative. A patient in compensated shock routinely minimizes, and the skin, the pulse, and the pressure are telling a different story.

The relative, since the relative knows the patient from day to day: Family often knows a baseline you cannot get any other way, and that history is genuinely useful. History from any source gets outranked by findings you generated yourself when the two disagree, and here they disagree sharply.

Establish intravenous access so dextrose can be given without delay: Access is the required step before dextrose and it does need to happen on this call. It comes after the airway and the ventilation, because a patient who is not moving air will not survive long enough for the sugar to matter.

Give oral glucose between the cheek and the gum: Oral glucose is a real treatment for hypoglycemia and it is fast to reach for. Anything placed in the mouth of an unresponsive patient with snoring respirations risks the airway you are trying to protect.

Recheck the glucose on a second site to confirm the reading: Repeating a number that disagrees with the patient is a good habit and glucometers do misread. This reading agrees with the patient completely, and the breathing is the emergency regardless of what the second stick says.

A normal neurologic exam and the absence of both fever and head trauma make a tension headache the most likely cause, so transport priority can remain routine: Tension headache is by far the most common headache an AEMT will actually meet, and a normal neurologic exam with no fever fits it well, which makes it the right call for a gradual, band-like headache that has built over hours and resembles ones the patient has had before. The onset is what does not fit, because a tension headache does not start abruptly at full intensity while the patient is sitting at rest. The key keeps the lethal diagnosis on the list until it can be excluded, and the asymmetry matters: being wrong about a tension headache costs a high-priority transport, while being wrong about a bleed costs the patient.

Because the vital signs and the neurologic exam are both unremarkable at this time, subarachnoid hemorrhage can reasonably be removed from active consideration: This is the same reasoning error as choice A, stated more explicitly, and it names the trap directly by using a reassuring exam to remove a diagnosis rather than to describe the current moment. Unremarkable vital signs and a normal neurologic exam are the expected findings early in subarachnoid hemorrhage, so they carry almost no power to exclude it. The key uses the identical findings correctly, as reassurance about how the patient is doing right now rather than as proof about what is causing it.

The elevated blood pressure reading confirms a hypertensive emergency as the underlying cause and should be the finding that guides transport priority: Hypertensive emergency is the right answer when a markedly elevated pressure is accompanied by evidence of end-organ damage, such as encephalopathy, pulmonary edema, chest pain from ischemia or dissection, or a focal neurologic deficit. A blood pressure of 148/92 is only mildly elevated and would not qualify even if those findings were present, and blood pressure commonly rises as a response to an intracranial event rather than as its cause. The key reads the elevated pressure as a consequence of what is happening inside the head, which is the direction the physiology actually runs here.