An on-call shift is the concentrated version of FY1: the same medicine, less backup in the building, more decisions per hour, and a bleep that does not care that you started yesterday. It is also, prepared for properly, the fastest clinical education available. This guide covers the preparation, the pattern for the common calls, and the escalation discipline that keeps everyone safe. One framing note before anything clinical: this is orientation, not a protocol; your trust's local guidance and your seniors outrank every sentence below.
Before the shift
Preparation is mostly logistics. Know the geography: which wards you cover, where they are, where the keys, toilets and water live. Load the phone: local antimicrobial guidance via MicroGuide or equivalent, the trust handbook, escalation pathways, switchboard, and one clinical reference you already use fluently, our suggested setup is at /blog/starting-fy1-2026-resources-on-my-phone. Know the team: who your SHO, registrar and outreach are tonight, and how to reach them by name. Eat before, carry food, and sleep beforehand like it is part of the job, because it is.
The shape of the common bleeps
Most on-call work is a small set of presentations arriving in random order, and each rewards the same discipline: go and assess rather than manage by phone, use ABCDE and the early warning score as your spine, and treat the observations chart's trend as more informative than any single number.
Fluids: the commonest task and quietly consequential. Assess status with your eyes and hands, not just the chart; check the kidneys, the sodium and the heart before prescribing; follow the local fluid policy; and reassess rather than write-and-walk.
Analgesia: assess the pain properly, prescribe up the ladder within local policy, and ask why the pain has changed, because new or escalating pain is a symptom first and a prescribing task second.
Fever: review the patient, not the temperature. Source-hunt systematically, culture before antibiotics where the situation allows, follow the local antimicrobial guide, and know your trust's sepsis pathway cold, because the febrile patient who is also hypotensive or newly confused has left this paragraph and entered the escalation one.
Hypoglycaemia: know where the local protocol lives before the shift; treat per that protocol promptly, recheck, and ask what caused it, the missed meal, the insulin dose, the deteriorating liver, because untreated causes recur at 5am.
Confusion: new confusion is a clinical finding, not a nuisance. Assess properly, screen the common reversibles, infection, hypoxia, glucose, drugs, retention, and document a baseline someone can compare against later.
Chest pain and breathlessness: assess in person, every time, with the full ABCDE, an ECG early for chest pain, and a low threshold for senior involvement; these two symptoms hide most of the night's genuinely dangerous diagnoses, and the escalation guide at /blog/ten-cases-every-new-fy1-should-escalate covers the patterns that must never wait.
Falls: assess for injury including head injury, check anticoagulation status, observations and the reason for the fall, and document thoroughly; the fall is often the presenting sign of the actual problem.
Escalation: the core on-call skill
The single behaviour that defines a safe new doctor: escalating early, in a form seniors can use. Before calling, collect the story into shape, the one-line problem, the observations and trend, what you have done, what you are asking, and deliver it as SBAR; our full guide to that call is at /blog/how-to-ask-a-senior-for-help-new-doctors. The threshold question is simple: if you are wondering whether this needs a senior, it does. Outreach and critical care exist to be called; the early warning score's escalation triggers are instructions, not suggestions.
Handover
The shift ends with its most safety-critical task. Hand over the sick, the pending and the conditional: who is unwell and what the plan is, which results are outstanding and what should happen at each possible answer, and what you were worried about even if you cannot fully say why. Written where your trust writes, spoken clearly, and never rushed because you are tired; the night team inherits your patients and your loose ends equally.
Frequently asked questions
What should I actually memorise before the first shift?
ABCDE until it is automatic, your local escalation numbers, and where the hypoglycaemia and sepsis protocols live. Everything else is legitimately look-up material, and knowing where to look fast is the skill; more on that balance at /blog/what-should-an-fy1-know-without-looking-it-up.
How do I keep learning from on-call rather than just surviving it?
Capture the questions the shift generated, the anticoagulation query, the fluid uncertainty, and chase them within the week, turning them into retrieval practice rather than relief. The shifts become a curriculum instead of a blur.
What should go in my pockets, physically?
Pen, spare pen, folded list, snack, and nothing else load-bearing: the phone carries the references, and the trust provides the rest. Travel light; you will walk miles.