diff --git a/.env.example b/.env.example
index 9d346ea19..4521ae6b3 100644
--- a/.env.example
+++ b/.env.example
@@ -103,6 +103,15 @@
 # SUMMARIZE_CHUNK_SIZE=400                       # When mem::summarize sees a session larger than this, it chunks observations and map-reduces (chunk-summarize → reduce-merge) to stay within the LLM's context window. Default 400 ≈ 50k tokens per chunk at ~110 tok/obs. Native sessions are capped by MAX_OBS_PER_SESSION; chunking primarily matters for bulk-imported jsonl sessions, which bypass that cap.
 # SUMMARIZE_CHUNK_CONCURRENCY=6                  # Parallel chunk LLM calls during chunked summarize. Default 6 fits ~100-chunk sessions under iii's 180s function-invocation timeout at typical ~8s/call. High-throughput providers (Novita, DeepInfra, DeepSeek) commonly allow 100+ concurrent — bump this for very large imported sessions.
 
+# Health monitor thresholds (/agentmemory/health). Defaults shown; unset to keep them.
+# AGENTMEMORY_HEALTH_EVENTLOOP_WARN_MS=100       # Event loop lag → degraded
+# AGENTMEMORY_HEALTH_EVENTLOOP_CRITICAL_MS=500   # Event loop lag → critical
+# AGENTMEMORY_HEALTH_CPU_WARN_PCT=80             # Process CPU % → degraded
+# AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT=90         # Process CPU % → critical
+# AGENTMEMORY_HEALTH_MEM_WARN_PCT=80             # Heap-used ratio % → degraded (RSS floor applies)
+# AGENTMEMORY_HEALTH_MEM_CRITICAL_PCT=95         # Heap-used ratio % → critical (RSS floor applies)
+# AGENTMEMORY_HEALTH_MEM_RSS_FLOOR_MB=512        # Min RSS (MiB) before memory alerts fire
+
 # -----------------------------------------------------------------------------
 # 5. Behaviour flags
 # -----------------------------------------------------------------------------
diff --git a/src/health/thresholds.ts b/src/health/thresholds.ts
index 7279afad1..4cc503c5d 100644
--- a/src/health/thresholds.ts
+++ b/src/health/thresholds.ts
@@ -20,11 +20,45 @@ const DEFAULTS: ThresholdConfig = {
   memoryRssFloorBytes: 512 * 1024 * 1024,
 };
 
+const ENV_VARS: Record<keyof ThresholdConfig, string> = {
+  eventLoopLagWarnMs: "AGENTMEMORY_HEALTH_EVENTLOOP_WARN_MS",
+  eventLoopLagCriticalMs: "AGENTMEMORY_HEALTH_EVENTLOOP_CRITICAL_MS",
+  cpuWarnPercent: "AGENTMEMORY_HEALTH_CPU_WARN_PCT",
+  cpuCriticalPercent: "AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT",
+  memoryWarnPercent: "AGENTMEMORY_HEALTH_MEM_WARN_PCT",
+  memoryCriticalPercent: "AGENTMEMORY_HEALTH_MEM_CRITICAL_PCT",
+  memoryRssFloorBytes: "AGENTMEMORY_HEALTH_MEM_RSS_FLOOR_MB",
+};
+
+function parseThreshold(raw: string | undefined): number | undefined {
+  if (raw === undefined || raw.trim() === "") return undefined;
+  const value = Number(raw);
+  return Number.isFinite(value) && value > 0 ? value : undefined;
+}
+
+export function thresholdOverridesFromEnv(
+  env: NodeJS.ProcessEnv = process.env,
+): Partial<ThresholdConfig> {
+  const overrides: Partial<ThresholdConfig> = {};
+  for (const key of Object.keys(ENV_VARS) as (keyof ThresholdConfig)[]) {
+    const parsed = parseThreshold(env[ENV_VARS[key]]);
+    if (parsed === undefined) continue;
+    if (key === "memoryRssFloorBytes") {
+      const bytes = parsed * 1024 * 1024;
+      if (!Number.isFinite(bytes)) continue;
+      overrides[key] = bytes;
+    } else {
+      overrides[key] = parsed;
+    }
+  }
+  return overrides;
+}
+
 export function evaluateHealth(
   snapshot: HealthSnapshot,
   config: Partial<ThresholdConfig> = {},
 ): { status: "healthy" | "degraded" | "critical"; alerts: string[]; notes: string[] } {
-  const cfg = { ...DEFAULTS, ...config };
+  const cfg = { ...DEFAULTS, ...thresholdOverridesFromEnv(), ...config };
   const alerts: string[] = [];
   const notes: string[] = [];
   let critical = false;
diff --git a/test/health-thresholds-env.test.ts b/test/health-thresholds-env.test.ts
new file mode 100644
index 000000000..0ef8e4c54
--- /dev/null
+++ b/test/health-thresholds-env.test.ts
@@ -0,0 +1,99 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("iii-sdk", () => ({
+  sdk: { trigger: vi.fn() },
+  kv: { get: vi.fn(), set: vi.fn(), list: vi.fn() },
+}));
+
+import {
+  evaluateHealth,
+  thresholdOverridesFromEnv,
+} from "../src/health/thresholds.js";
+import type { HealthSnapshot } from "../src/types.js";
+
+function snap(over: Partial<HealthSnapshot> = {}): HealthSnapshot {
+  return {
+    connectionState: "connected",
+    workers: [],
+    memory: { heapUsed: 0, heapTotal: 1, rss: 0, external: 0 },
+    cpu: { userMicros: 0, systemMicros: 0, percent: 0 },
+    eventLoopLagMs: 0,
+    uptimeSeconds: 1,
+    kvConnectivity: { status: "ok", latencyMs: 1 },
+    status: "healthy",
+    alerts: [],
+    ...over,
+  };
+}
+
+describe("thresholdOverridesFromEnv", () => {
+  it("returns no overrides when no env vars are set", () => {
+    expect(thresholdOverridesFromEnv({})).toEqual({});
+  });
+
+  it("parses every supported variable", () => {
+    const overrides = thresholdOverridesFromEnv({
+      AGENTMEMORY_HEALTH_EVENTLOOP_WARN_MS: "200",
+      AGENTMEMORY_HEALTH_EVENTLOOP_CRITICAL_MS: "900",
+      AGENTMEMORY_HEALTH_CPU_WARN_PCT: "70",
+      AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT: "85",
+      AGENTMEMORY_HEALTH_MEM_WARN_PCT: "75",
+      AGENTMEMORY_HEALTH_MEM_CRITICAL_PCT: "92",
+      AGENTMEMORY_HEALTH_MEM_RSS_FLOOR_MB: "1024",
+    });
+    expect(overrides).toEqual({
+      eventLoopLagWarnMs: 200,
+      eventLoopLagCriticalMs: 900,
+      cpuWarnPercent: 70,
+      cpuCriticalPercent: 85,
+      memoryWarnPercent: 75,
+      memoryCriticalPercent: 92,
+      memoryRssFloorBytes: 1024 * 1024 * 1024,
+    });
+  });
+
+  it("ignores missing, empty, non-numeric, and non-positive values", () => {
+    const overrides = thresholdOverridesFromEnv({
+      AGENTMEMORY_HEALTH_CPU_WARN_PCT: "",
+      AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT: "not-a-number",
+      AGENTMEMORY_HEALTH_MEM_WARN_PCT: "0",
+      AGENTMEMORY_HEALTH_MEM_CRITICAL_PCT: "-5",
+    });
+    expect(overrides).toEqual({});
+  });
+
+  it("rejects RSS floor values that overflow the MiB-to-bytes conversion", () => {
+    const overrides = thresholdOverridesFromEnv({
+      AGENTMEMORY_HEALTH_MEM_RSS_FLOOR_MB: "1e308",
+    });
+    expect(overrides).toEqual({});
+  });
+});
+
+describe("evaluateHealth env threshold overrides", () => {
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  it("applies env thresholds when evaluating", () => {
+    vi.stubEnv("AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT", "50");
+    const s = snap({ cpu: { userMicros: 0, systemMicros: 0, percent: 60 } });
+    const { status, alerts } = evaluateHealth(s);
+    expect(status).toBe("critical");
+    expect(alerts.some((a) => a.startsWith("cpu_critical_"))).toBe(true);
+  });
+
+  it("caller-supplied config wins over env", () => {
+    vi.stubEnv("AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT", "50");
+    const s = snap({ cpu: { userMicros: 0, systemMicros: 0, percent: 60 } });
+    const { status } = evaluateHealth(s, { cpuCriticalPercent: 90 });
+    expect(status).toBe("healthy");
+  });
+
+  it("invalid env values fall back to defaults", () => {
+    vi.stubEnv("AGENTMEMORY_HEALTH_CPU_CRITICAL_PCT", "bogus");
+    const s = snap({ cpu: { userMicros: 0, systemMicros: 0, percent: 95 } });
+    const { status } = evaluateHealth(s);
+    expect(status).toBe("critical");
+  });
+});