diff --git a/frontend/components/chat/add-patient-dialog.tsx b/frontend/components/chat/add-patient-dialog.tsx
new file mode 100644
index 0000000..fab5f2e
--- /dev/null
+++ b/frontend/components/chat/add-patient-dialog.tsx
@@ -0,0 +1,403 @@
+"use client";
+
+import { Plus, RefreshCw, X } from "lucide-react";
+import { type FormEvent, type ReactNode, useState } from "react";
+
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogClose,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { Input } from "@/components/ui/input";
+import { cn } from "@/lib/utils";
+import {
+  addPatient,
+  type AllergySeverity,
+  generateFileNumber,
+  type Patient,
+} from "@/lib/patients";
+
+type AddPatientDialogProps = {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  onCreated: (fileNumber: string) => void;
+};
+
+type AllergyDraft = { substance: string; reaction: string; severity: AllergySeverity };
+type MedicationDraft = { name: string; dose: string; frequency: string };
+
+const controlClass =
+  "h-9 w-full rounded-3xl border border-transparent bg-input/50 px-3 text-sm text-foreground outline-none transition-[color,box-shadow] focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/30";
+
+function Field({ label, children }: { label: string; children: ReactNode }) {
+  return (
+    <label className="flex flex-col gap-1.5">
+      <span className="text-xs text-muted-foreground">{label}</span>
+      {children}
+    </label>
+  );
+}
+
+function SectionHeader({
+  label,
+  onAdd,
+}: {
+  label: string;
+  onAdd: () => void;
+}) {
+  return (
+    <div className="flex items-center justify-between">
+      <span className="text-xs font-medium tracking-wide text-muted-foreground uppercase">
+        {label}
+      </span>
+      <Button onClick={onAdd} size="sm" type="button" variant="ghost">
+        <Plus className="size-4" />
+        Add
+      </Button>
+    </div>
+  );
+}
+
+function initialsFromName(name: string): string {
+  const parts = name.trim().split(/\s+/).filter(Boolean);
+  if (parts.length === 0) {
+    return "?";
+  }
+  return parts
+    .slice(0, 2)
+    .map((part) => part[0])
+    .join("")
+    .toUpperCase();
+}
+
+const today = () =>
+  new Date().toLocaleDateString("en-US", {
+    month: "short",
+    day: "2-digit",
+    year: "numeric",
+  });
+
+export function AddPatientDialog({
+  open,
+  onOpenChange,
+  onCreated,
+}: AddPatientDialogProps) {
+  // Lazily generate the file number on mount. The dialog is remounted (via a
+  // `key`) each time it opens, so this gives a fresh number + cleared form
+  // without a reset effect.
+  const [fileNumber, setFileNumber] = useState(generateFileNumber);
+  const [name, setName] = useState("");
+  const [age, setAge] = useState("");
+  const [sex, setSex] = useState<Patient["sex"]>("F");
+  const [status, setStatus] = useState<Patient["status"]>("active");
+  const [pcp, setPcp] = useState("");
+  const [bp, setBp] = useState("");
+  const [hr, setHr] = useState("");
+  const [temp, setTemp] = useState("");
+  const [spo2, setSpo2] = useState("");
+  const [allergies, setAllergies] = useState<AllergyDraft[]>([]);
+  const [medications, setMedications] = useState<MedicationDraft[]>([]);
+
+  const handleSubmit = (event: FormEvent<HTMLFormElement>) => {
+    event.preventDefault();
+    if (!name.trim()) {
+      return;
+    }
+
+    const patient: Patient = {
+      fileNumber,
+      name: name.trim(),
+      age: Number(age) || 0,
+      sex,
+      pcp: pcp.trim() || "—",
+      status,
+      initials: initialsFromName(name),
+      allergies: allergies.filter((a) => a.substance.trim()),
+      alerts: [],
+      medications: medications.filter((m) => m.name.trim()),
+      problems: [],
+      vitals: {
+        bp: bp.trim() || "—",
+        hr: hr.trim() || "—",
+        temp: temp.trim() || "—",
+        spo2: spo2.trim() || "—",
+        takenAt: today(),
+      },
+      vitalsTrend: { label: "Heart rate", unit: "bpm", points: [] },
+      labs: [],
+      labTrend: { label: "—", unit: "", points: [] },
+      encounters: [],
+    };
+
+    addPatient(patient);
+    onCreated(fileNumber);
+    onOpenChange(false);
+  };
+
+  return (
+    <Dialog onOpenChange={onOpenChange} open={open}>
+      <DialogContent className="max-h-[85dvh] overflow-y-auto sm:max-w-lg">
+        <DialogHeader>
+          <DialogTitle>Add patient</DialogTitle>
+          <DialogDescription>
+            Create a new chart. A file number has been generated for you.
+          </DialogDescription>
+        </DialogHeader>
+
+        <form className="flex flex-col gap-4" onSubmit={handleSubmit}>
+          <Field label="File number">
+            <div className="flex items-center gap-2">
+              <Input readOnly value={fileNumber} />
+              <Button
+                aria-label="Regenerate file number"
+                onClick={() => setFileNumber(generateFileNumber())}
+                size="icon"
+                type="button"
+                variant="outline"
+              >
+                <RefreshCw className="size-4" />
+              </Button>
+            </div>
+          </Field>
+
+          <Field label="Full name">
+            <Input
+              autoFocus
+              onChange={(event) => setName(event.target.value)}
+              placeholder="e.g. Jordan Pierce"
+              required
+              value={name}
+            />
+          </Field>
+
+          <div className="grid grid-cols-3 gap-3">
+            <Field label="Age">
+              <Input
+                inputMode="numeric"
+                onChange={(event) => setAge(event.target.value)}
+                placeholder="—"
+                value={age}
+              />
+            </Field>
+            <Field label="Sex">
+              <select
+                className={controlClass}
+                onChange={(event) => setSex(event.target.value as Patient["sex"])}
+                value={sex}
+              >
+                <option value="F">Female</option>
+                <option value="M">Male</option>
+              </select>
+            </Field>
+            <Field label="Status">
+              <select
+                className={controlClass}
+                onChange={(event) =>
+                  setStatus(event.target.value as Patient["status"])
+                }
+                value={status}
+              >
+                <option value="active">Active</option>
+                <option value="inpatient">Inpatient</option>
+                <option value="discharged">Discharged</option>
+              </select>
+            </Field>
+          </div>
+
+          <Field label="Primary care">
+            <Input
+              onChange={(event) => setPcp(event.target.value)}
+              placeholder="e.g. Dr. Lena Ortiz"
+              value={pcp}
+            />
+          </Field>
+
+          <div className="flex flex-col gap-1.5">
+            <span className="text-xs font-medium tracking-wide text-muted-foreground uppercase">
+              Current vitals
+            </span>
+            <div className="grid grid-cols-2 gap-3 sm:grid-cols-4">
+              <Input
+                aria-label="Blood pressure"
+                onChange={(event) => setBp(event.target.value)}
+                placeholder="BP"
+                value={bp}
+              />
+              <Input
+                aria-label="Heart rate"
+                onChange={(event) => setHr(event.target.value)}
+                placeholder="HR"
+                value={hr}
+              />
+              <Input
+                aria-label="Temperature"
+                onChange={(event) => setTemp(event.target.value)}
+                placeholder="Temp"
+                value={temp}
+              />
+              <Input
+                aria-label="Oxygen saturation"
+                onChange={(event) => setSpo2(event.target.value)}
+                placeholder="SpO₂"
+                value={spo2}
+              />
+            </div>
+          </div>
+
+          <div className="flex flex-col gap-2">
+            <SectionHeader
+              label="Allergies"
+              onAdd={() =>
+                setAllergies((prev) => [
+                  ...prev,
+                  { substance: "", reaction: "", severity: "mild" },
+                ])
+              }
+            />
+            {allergies.map((allergy, index) => (
+              <div className="flex items-center gap-2" key={index}>
+                <Input
+                  aria-label="Substance"
+                  onChange={(event) =>
+                    setAllergies((prev) =>
+                      prev.map((row, i) =>
+                        i === index
+                          ? { ...row, substance: event.target.value }
+                          : row
+                      )
+                    )
+                  }
+                  placeholder="Substance"
+                  value={allergy.substance}
+                />
+                <Input
+                  aria-label="Reaction"
+                  onChange={(event) =>
+                    setAllergies((prev) =>
+                      prev.map((row, i) =>
+                        i === index
+                          ? { ...row, reaction: event.target.value }
+                          : row
+                      )
+                    )
+                  }
+                  placeholder="Reaction"
+                  value={allergy.reaction}
+                />
+                <select
+                  aria-label="Severity"
+                  className={cn(controlClass, "w-auto")}
+                  onChange={(event) =>
+                    setAllergies((prev) =>
+                      prev.map((row, i) =>
+                        i === index
+                          ? {
+                              ...row,
+                              severity: event.target.value as AllergySeverity,
+                            }
+                          : row
+                      )
+                    )
+                  }
+                  value={allergy.severity}
+                >
+                  <option value="mild">Mild</option>
+                  <option value="moderate">Moderate</option>
+                  <option value="severe">Severe</option>
+                </select>
+                <button
+                  aria-label="Remove allergy"
+                  className="text-muted-foreground transition-colors hover:text-foreground"
+                  onClick={() =>
+                    setAllergies((prev) => prev.filter((_, i) => i !== index))
+                  }
+                  type="button"
+                >
+                  <X className="size-4" />
+                </button>
+              </div>
+            ))}
+          </div>
+
+          <div className="flex flex-col gap-2">
+            <SectionHeader
+              label="Medications"
+              onAdd={() =>
+                setMedications((prev) => [
+                  ...prev,
+                  { name: "", dose: "", frequency: "" },
+                ])
+              }
+            />
+            {medications.map((med, index) => (
+              <div className="flex items-center gap-2" key={index}>
+                <Input
+                  aria-label="Medication name"
+                  onChange={(event) =>
+                    setMedications((prev) =>
+                      prev.map((row, i) =>
+                        i === index ? { ...row, name: event.target.value } : row
+                      )
+                    )
+                  }
+                  placeholder="Name"
+                  value={med.name}
+                />
+                <Input
+                  aria-label="Dose"
+                  onChange={(event) =>
+                    setMedications((prev) =>
+                      prev.map((row, i) =>
+                        i === index ? { ...row, dose: event.target.value } : row
+                      )
+                    )
+                  }
+                  placeholder="Dose"
+                  value={med.dose}
+                />
+                <Input
+                  aria-label="Frequency"
+                  onChange={(event) =>
+                    setMedications((prev) =>
+                      prev.map((row, i) =>
+                        i === index
+                          ? { ...row, frequency: event.target.value }
+                          : row
+                      )
+                    )
+                  }
+                  placeholder="Frequency"
+                  value={med.frequency}
+                />
+                <button
+                  aria-label="Remove medication"
+                  className="text-muted-foreground transition-colors hover:text-foreground"
+                  onClick={() =>
+                    setMedications((prev) => prev.filter((_, i) => i !== index))
+                  }
+                  type="button"
+                >
+                  <X className="size-4" />
+                </button>
+              </div>
+            ))}
+          </div>
+
+          <DialogFooter>
+            <DialogClose render={<Button type="button" variant="outline" />}>
+              Cancel
+            </DialogClose>
+            <Button disabled={!name.trim()} type="submit">
+              Save patient
+            </Button>
+          </DialogFooter>
+        </form>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/frontend/components/chat/chat-input.tsx b/frontend/components/chat/chat-input.tsx
index e0a43da..efdeb74 100644
--- a/frontend/components/chat/chat-input.tsx
+++ b/frontend/components/chat/chat-input.tsx
@@ -11,6 +11,7 @@ import {
   Plus,
   Square,
   Stethoscope,
+  UserPlus,
   X,
 } from "lucide-react";
 import {
@@ -22,6 +23,7 @@ import {
   useState,
 } from "react";
 
+import { AddPatientDialog } from "@/components/chat/add-patient-dialog";
 import {
   DropdownMenu,
   DropdownMenuContent,
@@ -133,6 +135,9 @@ export function ChatInput({ onSubmit, status, onStop }: ChatInputProps) {
   const [specialty, setSpecialty] = useState("internal-medicine");
   const [facility, setFacility] = useState("main-hospital");
   const [timeRange, setTimeRange] = useState("12m");
+  const [addOpen, setAddOpen] = useState(false);
+  // Bumped on each open so the dialog remounts with a fresh file number + form.
+  const [addKey, setAddKey] = useState(0);
   const fileInputRef = useRef<HTMLInputElement>(null);
 
   const isGenerating = status === "submitted" || status === "streaming";
@@ -187,6 +192,7 @@ export function ChatInput({ onSubmit, status, onStop }: ChatInputProps) {
   }, []);
 
   return (
+    <>
     <form
       onSubmit={(event) => {
         event.preventDefault();
@@ -323,7 +329,26 @@ export function ChatInput({ onSubmit, status, onStop }: ChatInputProps) {
           triggerClassName={contextPill}
           value={timeRange}
         />
+        <button
+          className={cn(contextPill, "ml-auto")}
+          onClick={() => {
+            setAddKey((k) => k + 1);
+            setAddOpen(true);
+          }}
+          type="button"
+        >
+          <UserPlus className="size-4" />
+          <span>Add patient</span>
+        </button>
       </div>
     </form>
+
+    <AddPatientDialog
+      key={addKey}
+      onCreated={(fileNumber) => onSubmit(`/patient ${fileNumber}`)}
+      onOpenChange={setAddOpen}
+      open={addOpen}
+    />
+    </>
   );
 }
diff --git a/frontend/components/chat/patient-cards.tsx b/frontend/components/chat/patient-cards.tsx
index cd2bf7d..f4ed9de 100644
--- a/frontend/components/chat/patient-cards.tsx
+++ b/frontend/components/chat/patient-cards.tsx
@@ -85,7 +85,14 @@ function Row({ label, value }: { label: ReactNode; value: ReactNode }) {
   );
 }
 
+function Empty({ children }: { children: ReactNode }) {
+  return <p className="text-muted-foreground">{children}</p>;
+}
+
 function TrendBlock({ trend }: { trend: Trend }) {
+  if (trend.points.length === 0) {
+    return <Empty>No trend data yet.</Empty>;
+  }
   return (
     <div className="flex flex-col gap-1.5">
       <div className="flex items-baseline justify-between gap-2">
@@ -101,6 +108,9 @@ function TrendBlock({ trend }: { trend: Trend }) {
 }
 
 function TrendDetail({ trend }: { trend: Trend }) {
+  if (trend.points.length === 0) {
+    return <Empty>No trend data yet.</Empty>;
+  }
   const min = Math.min(...trend.points);
   const max = Math.max(...trend.points);
   return (
@@ -285,26 +295,30 @@ function LabsCard({ patient }: { patient: Patient }) {
     <ExpandableCard
       description={`As of ${patient.labs[0]?.takenAt ?? "—"}`}
       detail={
-        <div className="flex flex-col gap-4">
-          <div className="flex flex-col gap-2.5">
-            {patient.labs.map((lab) => (
-              <div
-                className="flex items-center justify-between gap-3"
-                key={lab.name}
-              >
-                <div className="flex flex-col">
-                  <span className="text-foreground">{lab.name}</span>
-                  <span className="text-xs text-muted-foreground">
-                    {lab.takenAt}
-                  </span>
+        patient.labs.length === 0 ? (
+          <Empty>No labs on file.</Empty>
+        ) : (
+          <div className="flex flex-col gap-4">
+            <div className="flex flex-col gap-2.5">
+              {patient.labs.map((lab) => (
+                <div
+                  className="flex items-center justify-between gap-3"
+                  key={lab.name}
+                >
+                  <div className="flex flex-col">
+                    <span className="text-foreground">{lab.name}</span>
+                    <span className="text-xs text-muted-foreground">
+                      {lab.takenAt}
+                    </span>
+                  </div>
+                  {labValue(lab.value, lab.flag)}
                 </div>
-                {labValue(lab.value, lab.flag)}
-              </div>
-            ))}
+              ))}
+            </div>
+            <Separator />
+            <TrendDetail trend={patient.labTrend} />
           </div>
-          <Separator />
-          <TrendDetail trend={patient.labTrend} />
-        </div>
+        )
       }
       title="Labs"
     >
@@ -313,34 +327,43 @@ function LabsCard({ patient }: { patient: Patient }) {
         <CardDescription>As of {patient.labs[0]?.takenAt ?? "—"}</CardDescription>
       </CardHeader>
       <CardContent className="flex flex-col gap-4">
-        <div className="flex flex-col gap-2">
-          {patient.labs.map((lab) => (
-            <Row
-              key={lab.name}
-              label={lab.name}
-              value={labValue(lab.value, lab.flag)}
-            />
-          ))}
-        </div>
-        <Separator />
-        <TrendBlock trend={patient.labTrend} />
+        {patient.labs.length === 0 ? (
+          <Empty>No labs on file.</Empty>
+        ) : (
+          <>
+            <div className="flex flex-col gap-2">
+              {patient.labs.map((lab) => (
+                <Row
+                  key={lab.name}
+                  label={lab.name}
+                  value={labValue(lab.value, lab.flag)}
+                />
+              ))}
+            </div>
+            <Separator />
+            <TrendBlock trend={patient.labTrend} />
+          </>
+        )}
       </CardContent>
     </ExpandableCard>
   );
 }
 
 function MedicationsCard({ patient }: { patient: Patient }) {
-  const list = (
-    <div className="flex flex-col gap-2">
-      {patient.medications.map((med) => (
-        <Row
-          key={med.name}
-          label={med.name}
-          value={`${med.dose} · ${med.frequency}`}
-        />
-      ))}
-    </div>
-  );
+  const list =
+    patient.medications.length === 0 ? (
+      <Empty>No active medications.</Empty>
+    ) : (
+      <div className="flex flex-col gap-2">
+        {patient.medications.map((med) => (
+          <Row
+            key={med.name}
+            label={med.name}
+            value={`${med.dose} · ${med.frequency}`}
+          />
+        ))}
+      </div>
+    );
   return (
     <ExpandableCard
       description={`${patient.medications.length} active`}
@@ -357,17 +380,20 @@ function MedicationsCard({ patient }: { patient: Patient }) {
 }
 
 function ProblemsCard({ patient }: { patient: Patient }) {
-  const list = (
-    <div className="flex flex-col gap-2">
-      {patient.problems.map((problem) => (
-        <Row
-          key={problem.label}
-          label={problem.label}
-          value={`since ${problem.since}`}
-        />
-      ))}
-    </div>
-  );
+  const list =
+    patient.problems.length === 0 ? (
+      <Empty>No active problems.</Empty>
+    ) : (
+      <div className="flex flex-col gap-2">
+        {patient.problems.map((problem) => (
+          <Row
+            key={problem.label}
+            label={problem.label}
+            value={`since ${problem.since}`}
+          />
+        ))}
+      </div>
+    );
   return (
     <ExpandableCard
       description={`${patient.problems.length} active`}
@@ -437,6 +463,9 @@ function AllergiesCard({ patient }: { patient: Patient }) {
 }
 
 function VisitsList({ patient }: { patient: Patient }) {
+  if (patient.encounters.length === 0) {
+    return <Empty>No visits yet.</Empty>;
+  }
   return (
     <div className="flex flex-col gap-3">
       {patient.encounters.map((encounter) => (
diff --git a/frontend/lib/patients.ts b/frontend/lib/patients.ts
index dad7553..2ef0c46 100644
--- a/frontend/lib/patients.ts
+++ b/frontend/lib/patients.ts
@@ -266,3 +266,18 @@ export async function getPatient(fileNumber: string): Promise<Patient | null> {
   await new Promise((resolve) => setTimeout(resolve, 700));
   return PATIENTS[fileNumber.trim()] ?? null;
 }
+
+// Generate a unique 5-digit file number not already in the store.
+export function generateFileNumber(): string {
+  let candidate: string;
+  do {
+    candidate = String(10000 + Math.floor(Math.random() * 89999));
+  } while (candidate in PATIENTS);
+  return candidate;
+}
+
+// Add (or replace) a patient in the in-memory store. Session-only — no backend
+// yet, so this resets on reload. Swap point for a real "create patient" API.
+export function addPatient(patient: Patient): void {
+  PATIENTS[patient.fileNumber] = patient;
+}