Today's USMLE Question of the Day, With the Explanation

Today's USMLE question of the day is already on this page: no account, no email address, nothing gated. Answer it and the full explanation opens immediately. The item changes once every 24 hours at 00:00 UTC, and the last seven days stay replayable from the archive strip.
Educational use only — these are not official NBME or USMLE questions.
Last 7 days
Days roll over at 00:00 UTC, so everyone sees the same question on the same date. A tick marks a day you got right, a cross one you missed.
A 66-year-old woman is in the hospital on day three after an emergency repair of a ruptured abdominal aortic aneurysm during which she was profoundly hypotensive for nearly an hour and received six units of packed red blood cells. She has since been hemodynamically stable, and her jugular venous pressure is normal with trace pedal edema. Urine output has fallen to 15 mL/h despite a 1-L crystalloid challenge yesterday. Serum blood urea nitrogen is 48 mg/dL and creatinine is 3.6 mg/dL, increased from 0.9 mg/dL preoperatively. Urinalysis shows a specific gravity of 1.010, trace protein, and no red blood cells. Microscopy shows numerous coarse, pigmented, muddy brown granular casts and renal tubular epithelial cells. Urine sodium is 58 mEq/L, urine osmolality is 305 mOsm/kg, and the fractional excretion of sodium is 3.1%. Renal ultrasonography shows normal-sized kidneys without hydronephrosis.
Which of the following is the most likely cause of this patient's acute kidney injury?
Select one answer. Scoring and the full explanation appear immediately.
How today's USMLE question of the day is chosen
One UTC date, one USMLE question of the day
The item is derived from the calendar date in Coordinated Universal Time, so everyone opening the page on the same date answers the same USMLE question of the day.
It changes exactly once every 24 hours at 00:00 UTC. There is no personal queue and no way to skip ahead to an easier USMLE question of the day.
The USMLE question of the day walks the pool with a stride of 25 against 72 items, and those two numbers share no common factor.
So the USMLE question of the day visits every item once across a 72-day cycle before anything repeats, and successive days land in different disciplines.
The USMLE question of the day archive and streak
Because the mapping is purely a function of the date, stepping back a day recomputes that day’s USMLE question of the day rather than reading it from a server.
Your answers, your current streak and your best streak live in this browser and are never uploaded, so no server knows which USMLE question of the day you got right.
The archive strip reaches back seven days, so a missed USMLE question of the day is recoverable on Friday but not a fortnight later.
Nothing about the USMLE question of the day is personalised either. It does not get easier when you struggle or skew toward the disciplines you keep missing.
If you want adaptive sequencing, that is a question bank’s job rather than a USMLE question of the day’s.
Step 1 USMLE question of the day: shared science
The USMLE question of the day rotates through 8 disciplines, from cardiology and renal through to pharmacology, always in the standard five-option format.
Most items are built on material serving both exams, and those are the days that work as a Step 1 question of the day: mechanism, pathophysiology, drug action, the physiology behind an abnormal laboratory value.
Say plainly what that means, because most services do not: there are no Step 1-exclusive items in the USMLE question of the day pool.
On a pre-clinical day one USMLE question of the day is a retrieval cue, not coverage — still better than the zero questions you do on a day with no plan.
Step 2 CK USMLE question of the day: management
The remaining items lean toward Step 2 CK reasoning, so a Step 2 CK question of the day usually asks for a decision rather than a mechanism.
The next diagnostic step, the drug to start or stop, the patient who can be discharged. Those are the days to slow down on, because management items punish pattern matching.
Difficulty is mixed rather than escalating, so some days the USMLE question of the day is a warm-up and some days it is not.
Every USMLE question of the day is original material written for this site, and laboratory values inside the stems follow the NBME reference sheet.
A free USMLE question of the day with no email
Every rival mails the USMLE question of the day
The established services ask for an address first: you subscribe, the USMLE question of the day reaches your inbox tomorrow, and the explanation sits one click further into somebody’s funnel.
That design exists because a USMLE question of the day is an efficient way to collect addresses, not because email makes the question better.
This USMLE question of the day is simply on the page instead.
The USMLE question of the day is in the HTML
The vignette, the five options and the explanation of each USMLE question of the day are present in the HTML the server sends.
So the USMLE question of the day opens on a shared computer, needs no account, and is readable the moment you arrive rather than tomorrow morning.
Nothing is contingent on handing over a contact detail, and there is nothing to unsubscribe from afterwards.
What a free USMLE question of the day costs you
Nothing will remind you about the USMLE question of the day. No message arrives at seven in the morning, and a browser that clears its storage resets the streak.
A recurring alarm pointed at this URL does the same job as the emailed USMLE question of the day, without putting your address on a list.
It also keeps the arrangement one where no server holds a record of which items you answered or how you did.
And free here means free. There is no tier above this USMLE question of the day, and the only thing an account would buy is carrying a streak between devices.
What one USMLE question of the day is worth
Read every USMLE question of the day explanation
In every USMLE question of the day the paragraph that matters explains why the distractor you nearly chose fails, because that is where the discriminating rule lives.
A right answer arrived at by luck is a wrong answer that has not happened yet, which is why the answer explanation is the point of a USMLE question of the day.
Keep a one-line note of the discipline whenever you miss a USMLE question of the day, the way you would in a QOTD log.
Over a few weeks the USMLE question of the day quietly becomes an audit of which subjects still feel unstable, and that list is worth more than the streak.
Five minutes, and what a daily question will not do
One USMLE question of the day will not carry a Step preparation, and it is not built to.
What the USMLE question of the day does well is keep retrieval practice running when a full block is not realistic: clinical rotations, post-call days, the week after an exam.
Recall spread across many short sessions survives longer than the same minutes in one sitting, and the hard part of spacing has never been the studying.
It is showing up on a day when nothing is scheduled. That is the entire job of the streak counter beside the USMLE question of the day.
A USMLE question of the day is a supplement, not a substitute. Timed blocks train pacing and stamina, and no daily habit replaces a scored practice form sat under exam conditions.
When one USMLE question of the day is not enough
When one discipline keeps appearing in your USMLE question of the day miss log, that is the cue to open a longer session in it.
So work a full set instead of one item with filters by subject and difficulty.
If today’s USMLE question of the day turns on a laboratory number, look up a value from today’s stem against the sheet you are given in the exam.
And to keep the USMLE question of the day alive through a dedicated block, fit daily items into a schedule.
Frequently asked questions
How the USMLE question of the day is picked, what it costs you, and what happens to your streak.
Does the USMLE question of the day need an account?
Neither an account nor an email address. Today’s USMLE question of the day is in the page before you touch anything, and the explanation opens the moment you answer.
When does the USMLE question of the day change?
At 00:00 UTC, exactly once every 24 hours. The USMLE question of the day comes from the calendar date in Coordinated Universal Time, so everyone answers the same vignette on the same date.
When does a USMLE question of the day come round again?
Not soon. The rotation steps through the pool with a stride of 25 against 72 items, so every USMLE question of the day appears once across a 72-day cycle before any repeats.
Which exams does the USMLE question of the day cover?
The USMLE question of the day rotates through 8 disciplines. Most items are written on material serving both Step 1 and Step 2 CK; the rest lean toward Step 2 CK management reasoning.
Can I replay a USMLE question of the day I missed?
Yes, for the last seven days. The archive strip recomputes each USMLE question of the day from its date, so stepping back returns exactly the item that was live then.
Does my USMLE question of the day streak follow me?
It starts over. Streak, best streak and saved answers live in this browser and are never uploaded, which is the price of a USMLE question of the day with no account.
Is this an official NBME question of the day?
No. Every USMLE question of the day here is original material written for this site, and nothing is reproduced from an official examination or a commercial bank.
Is the USMLE question of the day really free?
There is no tier above this one. The same USMLE question of the day, the same five options and the same explanation are what everybody gets, with nothing held back.
Where to go next
Every tool here is free, needs no account, and runs entirely in your browser.
Today’s USMLE question of the day is free, explained, and already on this page.
Not affiliated with, endorsed by, or sponsored by the NBME® or USMLE®. Original study items, not official questions, and not medical advice.