Missed Diagnoses on Call: One Question Each

Why these get missed

These misses rarely come from a lack of knowledge. The key detail sits in the blind spot of volunteered history, either because it is embarrassing, because it settled last week, or because the patient has already built their own story. That detail exists only if you ask for it.

Diagnosica's library encodes this. In the five cases below, the deciding fact is tagged "on specific probe" and wired to a red flag labelled "must elicit". Patients won't volunteer it, and the mark sheet expects you to go and get it.

One self-explanation: Neil Ashworth, 45, three weeks of back pain after lifting. He thinks he’s aggravated a slipped disc and that codeine’s bunging up his bladder, and he offers that story readily.

Post is narrow: five diagnoses, one question each, then you escalate. It’s about catching missed diagnoses on call by surfacing the hidden fact. For differential structure, see ranking what it could be. It stops at escalation on purpose, and it doesn’t tell you what to do to anybody.

The sentinel headache

For missed diagnoses on call, the single history move here is this: ask, "Has this happened before, even briefly, even if it went away?"

If you ask "do you get headaches", Andrew says no, because he rarely does. You need the question about a sudden one that settled.

"I've suddenly got the worst headache of my life and I've been sick." It peaked in seconds, two hours ago.

On that probe he admits a similar but milder thunderclap a week ago that resolved. He briefly blacked out at onset, and keeps becoming drowsy and losing the thread. This pattern is not migraine, which typically builds over minutes to hours in a pattern he has never had.

His blood pressure is 182/102, which can be a response to a bleed. If you label this primary malignant hypertension, you miss it.

The guideline that covers assessment and diagnosis of subarachnoid haemorrhage caused by a ruptured aneurysm is the NICE guideline on subarachnoid haemorrhage.

With these red flags, escalate early to a senior and defend your reasoning.

Saddle anaesthesia and retention with overflow

You won't catch this unless you ask two sensory questions. "When you wipe, does it feel normal down there?" and "When you go, can you feel it coming out?" Awkward, often skipped.

Neil Ashworth, 45, an AI patient, had three weeks of low back pain after lifting. Stoical and embarrassed about bladder and saddle symptoms, he insisted it was a slipped disc and codeine bunging his bladder.

He volunteered both legs felt weak and heavy, with unsteadiness worse over 48 hours. He would not volunteer numbness when wiping, two days of dribbling with constant fullness, loss of bladder sensation or urine flow, or new erectile difficulty.

Mechanical back pain is the dangerous under-call, one of the missed diagnoses on call. A lumbar X-ray is common, it cannot exclude compression, soft tissue is invisible, and a normal film misleads.

For shared language, see NICE guideline NG59, low back pain and sciatica in over 16s, assessment and management, the NICE low back pain guideline.

If those two questions reveal saddle anaesthesia or retention with overflow, do not accept a tidy story about codeine or a 'slipped disc'. Escalate to a senior now.

The five patients here are AI patients in Diagnosica’s case library, and you can take this history yourself; one free case a week, talk or type, it’s live and early so expect rough edges. Neil Ashworth is the one you’ve met; each patient hides one fact, and his is the saddle numbness and urinary retention the case checks you elicited.

Jaw claudication and transient greying of vision

Two questions to ask on a headache bleep: "Does your jaw ache or get tired when you're chewing, so you have to stop." "Has your sight gone dim or grey in one eye, even for a few seconds, even if it came straight back."

Gerald Hughes, 72, reports a new right temporal throbbing headache for three to four weeks, unlike any previous headache. Marked scalp tenderness too.

He won't mention chewing or eye symptoms unless asked. He thought tension, eye strain, or a trapped nerve, not a link.

On probe he admits jaw aching with chewing that makes him stop, and brief right eye greying. The tongue aches when he eats. It's worsened this week, and what scares him is the vision loss.

A tension-type headache doesn't cause jaw claudication, and a new headache at 72 needs a cause sought. A normal ESR doesn't fully exclude this, which is reasoning on the ward.

If either answer is yes, recognise red flags and escalate to a senior immediately.

Pain out of proportion to a soft abdomen

A 72-year-old with atrial fibrillation has sudden pain for six hours that he calls excruciating. He thinks it’s something he ate. Pain out of proportion to a soft abdomen is where missed diagnoses on call hide.

Ask the drug-history question, not another pain question: “Has anything changed with your blood thinner recently, has anyone stopped it.” He won’t offer a dental extraction two weeks ago or that his anticoagulant never restarted.

Observations won’t rescue you: heart rate 112, respiratory rate 24, blood pressure 106/64, temperature 37.4. The case records a soft abdomen with mild tenderness, no guarding, no rebound. A perforated ulcer is usually rigid and board-like, unlike this.

Early investigations are the trap. A normal lactate does not exclude it. A normal CRP early is common. A mildly raised amylase drags you toward pancreatitis then halts the work-up. A normal abdominal film excludes nothing, classic tests that change nothing.

The wrong turnings: acute pancreatitis, ruptured abdominal aortic aneurysm, perforated peptic ulcer, small bowel obstruction. Recognise the mismatch and the stopped anticoagulant, then escalate to a senior.

Getting sicker while already on antibiotics

Ask one thing first: when did the antibiotics start, and is this better or worse than yesterday?

Gary Nolan, 55 with diabetes, was started 24 hours ago for 'cellulitis' and he is deteriorating. That single trajectory answer flips the frame, a labelled infection on treatment reads as a solved problem on handover for a patient you've never met, but worsening on treatment says the label is wrong.

He tells you the pain is agonising and far beyond how the leg looks. Painkillers barely touch it.

Redness is spreading by the hour, past yesterday's pen line, and he feels 'like he is dying'. On specific probe he admits some patches are numb despite surrounding agony, and he describes a crackling sensation under one area of skin.

His observations are ugly, heart rate 128, respiratory rate 28, blood pressure 88 over 54, and a temperature of 39.1. Even a normal plain film would not settle this, gas shows in only a minority of cases.

He thinks they have not kicked in yet. Escalate to a senior now.

What to do with a suspicion

You escalate. You say out loud what you are worried about, to a named senior, now, and you say why. You are not expected to be certain, and you are not expected to sort it out yourself. Naming the suspicion is the job. Say it plainly, then ask how they want to proceed.

Know in advance who your senior is and how to reach them, whatever route your hospital uses. Geeky Medics explains team structure and escalation in the medical on-call shift, and we cover practical prep in covering your first set of nights.

Say it like this: "I've got a 45-year-old with three weeks of back pain who's now got saddle numbness and can't feel his bladder filling, and I'm worried about cauda equina." Mind The Bleep teaches leading with the worry, using SBAR, in escalating a deteriorating patient.

Calling with a suspicion that turns out to be nothing isn't failure. Sitting on one is.

On nights the misses are quiet rather than dramatic. Naming what you fear cuts the risk of missed diagnoses on call, from what I can tell. Early, and out loud.

Practise the questions, not the lists

You already know these five diagnoses. The miss is not knowledge, it's asking a stoical 45-year-old, out loud, if it feels normal when he wipes, and you do not build that by reading.

Diagnosica is an AI clinical simulator. You take a history from an AI patient by voice or text, order investigations, commit to a diagnosis and a management plan, defend your reasoning to an AI senior, and get a scorecard calibrated to the published exam mark sheets. Phone or laptop, no hardware.

Andrew, Neil, Gerald, Frank and Gary are AI patients in the library. They hide the same facts as in this post, and the case scores whether you elicit them. You can go and take the history yourself tonight.

It is live and early, so expect rough edges. One free case a week. Standard is $29 a month or $249 a year, and UK cards see £22 a month or £189 a year.

Diagnosica does not do physical examination practice: nothing in the library teaches physical signs. "It doesn't give advice about real patients, and it's not a diagnostic system. Treat every output as educational."

Educational use only. Not medical advice. AI-generated; verify clinically against primary sources.

Clinical review pending.

Practise these questions before nights You can run a case and be asked to surface the fact the patient will not volunteer, with one free case a week, Start free