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Chemical Pathology ST3 • 2027 Interview

The 2027 Chemical Pathology ST3 Interview Revision Platform: Question Bank, Live Practice and Mocks with Other Candidates

The Medibuddy Chemical Pathology ST3 Question Bank includes over 60 scenarios that closely mirror the real interview, each with a model answer written and edited by high-scoring candidates who sat the Chemical Pathology ST3 interview in 2026.

However, knowing a strong answer isn't the same as delivering it well under pressure, which is why we provide:

  • Study Groups with candidates across the country
  • Unlimited Live Mocks with other candidates
  • Peer Feedback on your mocks from a wide range of candidates

10 years' experience preparing doctors for interviews

We've spent a decade helping doctors prepare for specialty interviews, and candidates who've used Medibuddy Revision Platforms have secured some of the most competitive training posts in recent rounds.

Always up to date

Did you know the interviews change every year? That's why we review and update every Question Bank on the platform twice a year, so you know you're always practising with scenarios based on the latest interview structure.

Network and practise real interview scenarios with other candidates

Question Bank

See every scenario, and how to answer it well

Over 60 scenarios across all four interview stations, from electrolyte and endocrine work-ups to critical results and ethics, which tell you exactly how to respond to each one.
Study Groups

Connect with candidates across the country

Chemical pathology is a small specialty, so you may have few peers preparing locally. Study Groups connect you with candidates right across the country sitting the same interview.
Live MocksBeta

Practise interview technique with different candidates

Arrange or get matched on demand with other candidates and run real scenarios out loud under interview conditions. Those who practise with the widest range of people tend to score the highest.
Peer FeedbackBeta

Reviewed by candidates across the platform

Submit your recorded mocks to candidates across the platform and get honest, varied feedback. Reviewing other people's mocks teaches you just as much.

The question bank, and other candidates to practise with, all in one platform.

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Part 1 • See the questions

The Medibuddy 2027 Chemical Pathology ST3 Question Bank

Every station is tightly timed, so you have a limited window to deliver the high-scoring answers you need to do well. That means every point has to land, and knowing how to structure each answer is essential. That's why each of our 60-plus scenarios comes with a model answer, written by candidates who scored highly in the Chemical Pathology ST3 interview, so you know exactly how to approach every question the assessors put to you.
What's inside

What's included in the Chemical Pathology ST3 Question Bank

There's nothing worse than getting to the interview and being handed a scenario you've never seen before. Chemical pathology spans everything from sodium and calcium to inherited metabolic disease and the running of a laboratory, so the panel has a huge range of topics to draw on. That's why we cover all four stations, including the common work-ups and the more unusual cases, so you don't get caught out.

Clinical Biochemistry and Metabolic Medicine

Eighteen multi-part clinical scenarios, including hyponatraemia, acid-base, hypercalcaemia, adrenal testing, endocrine hypertension, hypoglycaemia, lipids, inherited metabolic disorders, porphyria, thyroid interference and toxicology, each showing you how to interpret results and advise a requesting clinician safely.

Communication

Phoning through critical results, declining an inappropriate request diplomatically, explaining familial hypercholesterolaemia or a positive newborn screen, and teaching colleagues about assay interference, with worked answers that keep you clear, structured and empathetic.

Ethics, Professionalism and Governance

Duty of candour after a laboratory error, incidental findings, consent and confidentiality in genetic testing, newborn screening ethics, conflicts of interest and whistleblowing, with answers that reference the right guidance and show how you'd act safely.

Academic and Presentation

Laboratory audit, closing the loop, quality improvement, critical appraisal of a diagnostic accuracy paper and research governance for stored samples, so you can present and defend your academic work with confidence.

Suitability and Commitment

Why chemical pathology, the dual laboratory and metabolic medicine role, the future of the specialty, your career path and your readiness for ST3, plus the personal skills questions on teamwork, supervision and working under pressure.
Built for 2027
Over 60 scenarios across seven assessed areas, written for the current four-station interview.
Try it

Try an example Chemical Pathology ST3 question

You are the Chemical Pathology ST3 registrar. A ward SHO calls you from the acute medical unit about a 74-year-old woman admitted yesterday with confusion and an unsteady gait. Her admission sodium was 118 mmol/L (reference range 133 to 146 mmol/L). She takes sertraline 100 mg, bendroflumethiazide 2.5 mg and ramipril 5 mg once daily, and has a background of heart failure (ejection fraction 35%) and type 2 diabetes. The SHO asks for your advice on the biochemical work-up.

How would you advise them?

Question
What would you want to know from the SHO before advising?
Example answer
First I'd confirm the result is genuine and gauge how severe and how acute it is, because that drives everything else. I'd ask how quickly the confusion developed, since symptoms over less than 48 hours point to acute hyponatraemia, and whether there's been vomiting, headache or seizures. I'd go through her medication carefully, as sertraline and bendroflumethiazide are both common culprits, and ask about fluid intake, recent losses and any chest, CNS, thyroid or adrenal history. Most importantly, I'd ask the SHO to assess her volume status, including JVP, oedema, postural blood pressure and mucous membranes, so we can class her as hypovolaemic, euvolaemic or hypervolaemic before choosing tests.
Question
Which investigations would you request, and why?
Example answer
I'd work through it stepwise. Plasma osmolality, glucose and lipids come first, to exclude pseudohyponatraemia and hypertonic causes such as hyperglycaemia. Then paired urine osmolality and urine sodium, which is the key discriminating step: a urine osmolality above 100 mOsm/kg means the kidney is inappropriately holding on to free water, and a urine sodium above 30 mmol/L in a euvolaemic patient off diuretics supports SIADH. Alongside that I'd request urea, creatinine, potassium, thyroid function, a 9am cortisol (with a short Synacthen test if adrenal insufficiency is suspected), urate and liver function, so the common mimics are excluded before anyone labels this SIADH.
Question
Plasma osmolality is 248, urine osmolality 510 and urine sodium 52, but she has a raised JVP and ankle oedema. How do you interpret this?
Example answer
The biochemistry fits SIADH: low plasma osmolality with inappropriately concentrated urine, ongoing renal sodium loss, a low urate, and normal renal, thyroid and adrenal function. The difficulty is that she also has heart failure with signs of fluid overload. Hypervolaemic hyponatraemia from heart failure would usually show a urine sodium under 20 mmol/L, so the high urine sodium points instead to the thiazide or a coexisting SIADH. My interpretation is drug-induced hyponatraemia with an SIADH pattern, from the sertraline and thiazide, on a background of heart failure. I'd advise stopping the thiazide now, reviewing the sertraline urgently with the prescribing team, and optimising her heart failure in parallel.
Question
The medical registrar asks how quickly her sodium should be corrected. How do you advise?
Example answer
The rate is guided by duration and symptoms rather than the number itself, and overcorrection is as dangerous as undercorrection. This is chronic, or of unknown duration, so I'd limit the rise to 10 mmol/L in the first 24 hours and 8 mmol/L in each 24 hours after that, aiming lower in high-risk patients. She's confused but not seizing, so she doesn't need hypertonic saline. I'd advise fluid restriction, stopping the thiazide, avoiding hypotonic fluids and checking sodium four-hourly, and ask the team to call me straight away if it rises by more than 4 to 5 mmol/L in the first six hours.
Question
At 18 hours her sodium has risen by 13 mmol/L and she's more alert. What now?
Example answer
Even though she looks better, this is beyond the safe limit and puts her at risk of osmotic demyelination syndrome, which can appear days later and may be irreversible. I'd phone the team immediately, speak to the medical consultant and inform my own consultant. Re-lowering is recommended once the limit is breached, using 5% glucose and, under consultant supervision, desmopressin to stop further free water loss, with close sodium monitoring. I'd also report it as a clinical incident and work out why correction was faster than expected, for example a water diuresis once the offending drugs were stopped.

That's one scenario. There are over 60 more.

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Actively maintained

How we keep our Question Banks up to date

The Chemical Pathology ST3 interview changes from year to year, and the biggest fear for any candidate is getting to interview day and realising you've revised with a question bank that's totally outdated.

That's why we review and update every Question Bank twice a year, so you know you're revising with scenarios that are likely to come up. We do this in April after the previous year's interviews, and again in October when the new recruitment guidance is published.

Built for 2027 interviews

Over 60 scenarios written for the current four-station format, covering the clinical, communication, ethics and professionalism, academic and commitment questions the panel draws on.

Updated for 2027 Interviews
Part 2 • Practise them live

The only interview resource where you can practise live with other candidates from across the country

Our Chemical Pathology ST3 Question Bank tells you exactly how to answer real interview scenarios. But how you practise with them will determine how many marks you score. Simply reading answers off a screen won't prepare you for the intense scrutiny you'll face in the interview. And in a specialty this small, practising with the same few colleagues limits the amount of feedback you'll get. Medibuddy gives you unique access to Chemical Pathology ST3 candidates across the country, so you can learn from a variety of perspectives and hear a far wider range of feedback than your own circle could ever give you.

Study Groups
When you prepare in isolation, you're relying on your own interpretation of the interview process, which is one of the quickest ways to get found out on the day. Study Groups connect you with other doctors across the country who are also applying to Chemical Pathology ST3, so you can engage and network with people preparing for the same interview as you. Everyone brings different experience from different hospitals, laboratories and training routes, meaning you won't ever miss out on the key bits of information that could swing the interview in your favour.
Live MocksBeta
Candidates who don't take part in mocks often struggle to adapt to the pressure of the interview. Your knowledge might be correct, but without convincing delivery the assessors will score you poorly. The best way to improve your delivery is to take part in as many live mocks as possible, which is why we haven't put a cap on how many you can do. We also know how difficult it can be to organise mocks with other people, so all you have to do is join the waiting room and we'll match you with a different Chemical Pathology ST3 candidate each time. Take turns as both the interviewer and candidate on real Question Bank scenarios, so you can see exactly how other candidates perform in real time, while refining your own interview technique.
Peer FeedbackBeta
Preparing alone means you won't know how you're coming across during the interview. And preparing with the same few candidates means you'll miss opportunities to improve, which is why it's so important to get as many opinions as possible on your performance. With Medibuddy, you can record a mock and submit it for feedback from other candidates on the platform, so you receive a wider range of feedback and refine your answers with each person you practise with. Reviewing other people's mocks is just as valuable, as it shows you how strong candidates handle the same scenarios, which is one of the fastest ways to improve.
The interview

What to expect from the Chemical Pathology ST3 interview

Chemical pathology is a small specialty with only around 20 ST3 posts across the UK each year. Competition has been rising, with around 2.3 applicants for every post in 2025, up from 1.44 the year before, so strong candidates are often separated by just a few marks at interview.

The interview is held online and runs as four stations, each scored independently by two assessors.

Station 1

Presentation

A short prepared presentation followed by questions from the panel. Our academic scenarios on critical appraisal, audit and quality improvement help you build a talk you can deliver clearly and defend confidently.
Station 2

Clinical

A clinical biochemistry or metabolic medicine scenario, often framed as advising a requesting clinician. Our multi-part work-ups show you how to interpret results and give safe, structured advice.
Station 3

Ethics and Professionalism

An ethical, professional or governance dilemma, often set in the laboratory. Our worked answers show you how to reason through it, refer to the right guidance and act safely.
Station 4

Suitability and Commitment to Specialty

Questions on why chemical pathology, your career so far and your readiness for ST3. Our answers show you how to evidence your commitment rather than simply list achievements.

How the interview is scored

All four stations are marked against the Chemical Pathology ST3 person specification. Our model answers are structured against those criteria, so you know exactly what a strong, well-organised answer looks like at each station.
Get ready

How to prepare for the Chemical Pathology ST3 interview

Start with the Question Bank

Work through 60+ scenarios across all four stations, each with a worked answer from a candidate who scored well in the 2026 interview. Start by reading how a strong answer is formed, then think about how you'd deliver it.

Talk the hard ones through in Study Groups

Study groups are your biggest opportunity to network and connect with other candidates sitting the same interview as you, which matters all the more in a small specialty. Everyone on the platform is in the same boat as you, so don't be scared to get involved and ask questions. After all, someone in your study group might just help you work through a scenario you've been struggling with.

Rehearse out loud in Live Mocks

Live mocks are where you begin to put everything you've learned into practice, and we know from experience that those who practise with a wide range of candidates usually do the best. So organise mocks with people from one of your study groups, or get matched with a random Chemical Pathology ST3 candidate, then take turns as interviewer and candidate using real scenarios until answering out loud under pressure feels normal.

Get reviewed with Peer Feedback before the day

Once you've recorded a mock, you can have other community members review it. This allows you to see how you come across to other people, and gives you time to refine your delivery as you revise, rather than being caught out on the day. Reviewing other people's mocks is just as crucial, as you can see how other candidates navigate the same scenarios as you.
Questions

Frequently asked questions

What does the Chemical Pathology ST3 interview involve?
The interview is held online across four stations: a presentation, a clinical scenario, ethics and professionalism, and suitability and commitment to the specialty. Each station is scored independently by two assessors against the person specification.
How competitive is the Chemical Pathology ST3 interview?
In 2025 there were around 2.3 applicants for every post, up from 1.44 the year before. With only around 20 posts each year, how well you prepare for the interview often makes the difference.
Does the Question Bank cover metabolic medicine?
Yes. Alongside the core clinical biochemistry work-ups, it covers lipid clinic management, inherited metabolic disorders and newborn screening, nutrition and refeeding, and metabolic and obesity clinic consultations.
Who writes the model answers?
High-scoring candidates who sat the Chemical Pathology ST3 interview in 2026.
Can I practise with other candidates?
Yes. Every Revision Platform purchase gives you the opportunity to connect with other candidates through Study Groups, Live Mocks and Peer Feedback.
How do the Live Mocks work?
All you have to do is join the waiting room, and we match you with another Chemical Pathology ST3 candidate. You can then take turns as interviewer and candidate on real Question Bank scenarios, allowing you to gain experience answering out loud to a real person before you ever sit in front of the panel.
What are Study Groups and how do they help?
Study groups are community forums for doctors across the country preparing for the same Chemical Pathology ST3 interview. You can ask questions, share what you're struggling with, and compare how you'd approach a scenario.
Can I get feedback on my interview performance?
Yes. After you've recorded a mock, you can ask other members to review it, allowing you to see which part of your answer needs fine-tuning.
Why use Medibuddy over other Chemical Pathology ST3 question banks?
We've been preparing doctors for specialty interviews for 10 years, and our model answers are written by candidates who've recently scored well in this interview. That means the scenarios reflect the interview you're about to sit. And it doesn't just stop at a question bank. Every purchase includes access to Study Groups, Live Mocks and Peer Feedback, so you can revise alongside candidates across the country.
How do you keep the Chemical Pathology ST3 Question Bank up to date?
We review and update it twice a year. In April after that year's interviews, and again in October when the new recruitment guidance is published. For the 2027 interview, every scenario has been written for the current four-station format.
How long do I get access for?
Access runs for 12 months from the purchase date.

Start preparing for the Chemical Pathology ST3 interview

The Revision Platform gives you over 60 scenarios to practise and refine with other candidates through Study Groups, Live Mocks and Peer Feedback.

Written by candidates who recently scored well in this interview, and updated twice a year, it's built to reflect the interview you're about to sit.

Instant access on web and the Medibuddy app • Study Groups, Live Mocks and Peer Feedback with every purchase • 12 months' access

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