diff --git a/server/api/region_test.go b/server/api/region_test.go
index 4d4b31e93d3e..6a5240eedbb5 100644
--- a/server/api/region_test.go
+++ b/server/api/region_test.go
@@ -171,15 +171,13 @@ func (suite *regionTestSuite) TestRegion() {
 func (suite *regionTestSuite) TestRegionCheck() {
 	re := suite.Require()
 	re.NoError(failpoint.Enable("github.com/tikv/pd/server/cluster/skipSleep", `return(true)`))
-	tu.Eventually(re, func() bool {
-		return suite.svr.GetRaftCluster().GetLastRegionStats() != nil
-	})
-	r := newTestRegionInfo(2, 1, []byte("a"), []byte("b"))
+	r := newTestRegionInfo(2, 1, []byte("a"), []byte(""))
 	downPeer := &metapb.Peer{Id: 13, StoreId: 2}
 	r = r.Clone(core.WithAddPeer(downPeer), core.WithDownPeers([]*pdpb.PeerStats{{Peer: downPeer, DownSeconds: 3600}}), core.WithPendingPeers([]*metapb.Peer{downPeer}))
-
 	mustRegionHeartbeat(re, suite.svr, r)
-	time.Sleep(150 * time.Millisecond)
+	tu.Eventually(re, func() bool {
+		return !suite.svr.GetRaftCluster().IsLastRegionStatsEmpty()
+	})
 	url := fmt.Sprintf("%s/region/id/%d", suite.urlPrefix, r.GetID())
 	r1 := &RegionInfo{}
 	suite.NoError(tu.ReadGetJSON(re, testDialClient, url, r1))
diff --git a/server/cluster/cluster.go b/server/cluster/cluster.go
index c48fe0cef15d..54d650e8c5af 100644
--- a/server/cluster/cluster.go
+++ b/server/cluster/cluster.go
@@ -270,6 +270,7 @@ func (c *RaftCluster) Start(s Server) error {
 	c.storeConfigManager = config.NewStoreConfigManager(c.httpClient)
 	c.coordinator = newCoordinator(c.ctx, cluster, s.GetHBStreams())
 	c.regionStats = statistics.NewRegionStatistics(c.opt, c.ruleManager, c.storeConfigManager)
+	c.lastRegionStats = statistics.NewRegionStatistics(c.opt, c.ruleManager, c.storeConfigManager)
 	c.limiter = NewStoreLimiter(s.GetPersistOptions())
 
 	c.wg.Add(8)
@@ -793,14 +794,6 @@ func (c *RaftCluster) processRegionHeartbeat(region *core.RegionInfo) error {
 	// Save to cache if meta or leader is updated, or contains any down/pending peer.
 	// Mark isNew if the region in cache does not have leader.
 	isNew, saveKV, saveCache, needSync := regionGuide(region, origin)
-	if !saveKV && !saveCache && !isNew {
-		// Due to some config changes need to update the region stats as well,
-		// so we do some extra checks here.
-		if c.regionStats != nil && c.regionStats.RegionStatsNeedUpdate(region) {
-			c.regionStats.Observe(region, c.getRegionStoresLocked(region))
-		}
-		return nil
-	}
 
 	failpoint.Inject("concurrentRegionHeartbeat", func() {
 		time.Sleep(500 * time.Millisecond)
@@ -976,9 +969,9 @@ func (c *RaftCluster) GetAverageRegionSize() int64 {
 	return c.core.GetAverageRegionSize()
 }
 
-// GetLastRegionStats returns region statistics from cluster. Only for test purpose.
-func (c *RaftCluster) GetLastRegionStats() *statistics.RegionStatistics {
-	return c.lastRegionStats
+// IsLastRegionStatsEmpty returns if region statistics is empty. Only for test purpose.
+func (c *RaftCluster) IsLastRegionStatsEmpty() bool {
+	return c.lastRegionStats.IsEmpty()
 }
 
 // DropCacheRegion removes a region from the cache.
@@ -1808,16 +1801,15 @@ func (c *RaftCluster) resetMetrics() {
 }
 
 func (c *RaftCluster) collectStatsMetrics() {
-	c.Lock()
-	defer c.Unlock()
-	if c.regionStats == nil {
+	if c.regionStats == nil || c.lastRegionStats == nil {
 		return
 	}
 	c.regionStats.Collect()
 	c.labelLevelStats.Collect()
-	c.lastRegionStats = c.regionStats.Clone()
-	c.labelLevelStats = statistics.NewLabelStatistics()
-	c.regionStats = statistics.NewRegionStatistics(c.opt, c.ruleManager, c.storeConfigManager)
+	lastStats := c.regionStats.GetStats()
+	c.lastRegionStats.SetStats(lastStats)
+	c.labelLevelStats.ResetStats()
+	c.regionStats.ResetStats()
 }
 
 func (c *RaftCluster) collectHotStatsMetrics() {
@@ -1826,10 +1818,11 @@ func (c *RaftCluster) collectHotStatsMetrics() {
 }
 
 func (c *RaftCluster) resetClusterMetrics() {
-	if c.regionStats == nil {
+	if c.regionStats == nil || c.lastRegionStats == nil {
 		return
 	}
 	c.regionStats.Reset()
+	c.lastRegionStats.Reset()
 	c.labelLevelStats.Reset()
 	// reset hot cache metrics
 	c.hotStat.ResetMetrics()
@@ -1863,8 +1856,6 @@ func (c *RaftCluster) resetProgressIndicator() {
 
 // GetRegionStatsByType gets the status of the region by types.
 func (c *RaftCluster) GetRegionStatsByType(typ statistics.RegionStatisticType) []*core.RegionInfo {
-	c.RLock()
-	defer c.RUnlock()
 	if c.lastRegionStats == nil {
 		return nil
 	}
@@ -1872,8 +1863,6 @@ func (c *RaftCluster) GetRegionStatsByType(typ statistics.RegionStatisticType) [
 }
 
 func (c *RaftCluster) updateRegionStats(regions []*core.RegionInfo) {
-	c.Lock()
-	defer c.Unlock()
 	for _, region := range regions {
 		if c.regionStats != nil {
 			c.regionStats.Observe(region, c.getRegionStoresLocked(region))
diff --git a/server/cluster/cluster_test.go b/server/cluster/cluster_test.go
index 9ffa0ee62ad2..43c69d67a825 100644
--- a/server/cluster/cluster_test.go
+++ b/server/cluster/cluster_test.go
@@ -934,25 +934,32 @@ func TestRegionSizeChanged(t *testing.T) {
 	re := require.New(t)
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
+	re.NoError(failpoint.Enable("github.com/tikv/pd/server/cluster/skipSleep", `return(true)`))
 
 	_, opt, err := newTestScheduleConfig()
 	re.NoError(err)
 	cluster := newTestRaftCluster(ctx, mockid.NewIDAllocator(), opt, storage.NewStorageWithMemoryBackend(), core.NewBasicCluster())
 	cluster.coordinator = newCoordinator(ctx, cluster, nil)
+	cluster.regionLabeler, _ = labeler.NewRegionLabeler(ctx, cluster.storage, time.Second*5)
 	cluster.regionStats = statistics.NewRegionStatistics(cluster.GetOpts(), cluster.ruleManager, cluster.storeConfigManager)
+	cluster.lastRegionStats = statistics.NewRegionStatistics(cluster.GetOpts(), cluster.ruleManager, cluster.storeConfigManager)
+	cluster.coordinator.wg.Add(1)
+	go cluster.coordinator.collectRegionStats()
 	region := newTestRegions(1, 3, 3)[0]
 	cluster.opt.GetMaxMergeRegionKeys()
 	curMaxMergeSize := int64(cluster.opt.GetMaxMergeRegionSize())
 	curMaxMergeKeys := int64(cluster.opt.GetMaxMergeRegionKeys())
 	region = region.Clone(
 		core.WithLeader(region.GetPeers()[2]),
+		core.WithEndKey([]byte{}),
 		core.SetApproximateSize(curMaxMergeSize-1),
 		core.SetApproximateKeys(curMaxMergeKeys-1),
 		core.SetFromHeartbeat(true),
 	)
 	cluster.processRegionHeartbeat(region)
 	regionID := region.GetID()
-	re.True(cluster.regionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
+	time.Sleep(150 * time.Millisecond)
+	re.True(cluster.lastRegionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
 	// Test ApproximateSize and ApproximateKeys change.
 	region = region.Clone(
 		core.WithLeader(region.GetPeers()[2]),
@@ -961,16 +968,20 @@ func TestRegionSizeChanged(t *testing.T) {
 		core.SetFromHeartbeat(true),
 	)
 	cluster.processRegionHeartbeat(region)
-	re.False(cluster.regionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
+	time.Sleep(150 * time.Millisecond)
+	re.False(cluster.lastRegionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
 	// Test MaxMergeRegionSize and MaxMergeRegionKeys change.
 	cluster.opt.SetMaxMergeRegionSize((uint64(curMaxMergeSize + 2)))
 	cluster.opt.SetMaxMergeRegionKeys((uint64(curMaxMergeKeys + 2)))
 	cluster.processRegionHeartbeat(region)
-	re.True(cluster.regionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
+	time.Sleep(150 * time.Millisecond)
+	re.True(cluster.lastRegionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
 	cluster.opt.SetMaxMergeRegionSize((uint64(curMaxMergeSize)))
 	cluster.opt.SetMaxMergeRegionKeys((uint64(curMaxMergeKeys)))
 	cluster.processRegionHeartbeat(region)
-	re.False(cluster.regionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
+	time.Sleep(150 * time.Millisecond)
+	re.False(cluster.lastRegionStats.IsRegionStatsType(regionID, statistics.UndersizedRegion))
+	re.NoError(failpoint.Disable("github.com/tikv/pd/server/cluster/skipSleep"))
 }
 
 func TestConcurrentReportBucket(t *testing.T) {
@@ -1209,6 +1220,7 @@ func TestOfflineAndMerge(t *testing.T) {
 	re := require.New(t)
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
+	re.NoError(failpoint.Enable("github.com/tikv/pd/server/cluster/skipSleep", `return(true)`))
 
 	_, opt, err := newTestScheduleConfig()
 	re.NoError(err)
@@ -1222,7 +1234,10 @@ func TestOfflineAndMerge(t *testing.T) {
 		}
 	}
 	cluster.regionStats = statistics.NewRegionStatistics(cluster.GetOpts(), cluster.ruleManager, cluster.storeConfigManager)
+	cluster.lastRegionStats = statistics.NewRegionStatistics(cluster.GetOpts(), cluster.ruleManager, cluster.storeConfigManager)
 	cluster.coordinator = newCoordinator(ctx, cluster, nil)
+	cluster.coordinator.wg.Add(1)
+	go cluster.coordinator.collectRegionStats()
 
 	// Put 4 stores.
 	for _, store := range newTestStores(4, "5.0.0") {
@@ -1261,14 +1276,17 @@ func TestOfflineAndMerge(t *testing.T) {
 		regions = core.SplitRegions(regions)
 	}
 	heartbeatRegions(re, cluster, regions)
+	time.Sleep(150 * time.Millisecond)
 	re.Len(cluster.GetRegionStatsByType(statistics.OfflinePeer), len(regions))
 
 	// Merge.
 	for i := 0; i < n; i++ {
 		regions = core.MergeRegions(regions)
 		heartbeatRegions(re, cluster, regions)
+		time.Sleep(150 * time.Millisecond)
 		re.Len(cluster.GetRegionStatsByType(statistics.OfflinePeer), len(regions))
 	}
+	re.NoError(failpoint.Disable("github.com/tikv/pd/server/cluster/skipSleep"))
 }
 
 func TestSyncConfig(t *testing.T) {
diff --git a/server/cluster/coordinator.go b/server/cluster/coordinator.go
index c3fdebf902d9..8dc9b23eb813 100644
--- a/server/cluster/coordinator.go
+++ b/server/cluster/coordinator.go
@@ -215,7 +215,6 @@ func (c *coordinator) collectRegionStats() {
 			key = nil
 			continue
 		}
-
 		key = regions[length-1].GetEndKey()
 		c.cluster.updateRegionStats(regions)
 		if len(key) == 0 {
diff --git a/server/cluster/coordinator_test.go b/server/cluster/coordinator_test.go
index 01f400a3e802..4875d1f8fdbb 100644
--- a/server/cluster/coordinator_test.go
+++ b/server/cluster/coordinator_test.go
@@ -243,6 +243,7 @@ func TestCollectMetrics(t *testing.T) {
 
 	tc, co, cleanup := prepare(nil, func(tc *testCluster) {
 		tc.regionStats = statistics.NewRegionStatistics(tc.GetOpts(), nil, tc.storeConfigManager)
+		tc.lastRegionStats = statistics.NewRegionStatistics(tc.GetOpts(), nil, tc.storeConfigManager)
 	}, func(co *coordinator) { co.run() }, re)
 	defer cleanup()
 
diff --git a/server/statistics/region_collection.go b/server/statistics/region_collection.go
index 9a58ab537cac..13f2d3b0c174 100644
--- a/server/statistics/region_collection.go
+++ b/server/statistics/region_collection.go
@@ -48,6 +48,8 @@ var statsTypes = []RegionStatisticType{
 	OfflinePeer,
 	LearnerPeer,
 	EmptyRegion,
+	OversizedRegion,
+	UndersizedRegion,
 }
 
 const nonIsolation = "none"
@@ -246,25 +248,60 @@ func (r *RegionStatistics) Collect() {
 	regionStatusGauge.WithLabelValues("undersized-region-count").Set(float64(len(r.stats[UndersizedRegion])))
 }
 
+// SetStats sets the statistics to the given one.
+func (r *RegionStatistics) SetStats(s map[RegionStatisticType]map[uint64]*RegionInfo) {
+	r.Lock()
+	defer r.Unlock()
+	r.stats = s
+}
+
+// ResetStats resets the statistics.
+func (r *RegionStatistics) ResetStats() {
+	r.Lock()
+	defer r.Unlock()
+	r.stats = make(map[RegionStatisticType]map[uint64]*RegionInfo)
+	r.index = make(map[uint64]RegionStatisticType)
+
+	r.stats[MissPeer] = make(map[uint64]*RegionInfo)
+	r.stats[ExtraPeer] = make(map[uint64]*RegionInfo)
+	r.stats[DownPeer] = make(map[uint64]*RegionInfo)
+	r.stats[PendingPeer] = make(map[uint64]*RegionInfo)
+	r.stats[OfflinePeer] = make(map[uint64]*RegionInfo)
+	r.stats[LearnerPeer] = make(map[uint64]*RegionInfo)
+	r.stats[EmptyRegion] = make(map[uint64]*RegionInfo)
+	r.stats[OversizedRegion] = make(map[uint64]*RegionInfo)
+	r.stats[UndersizedRegion] = make(map[uint64]*RegionInfo)
+}
+
+// IsEmpty returns if the region statistics is empty. Only for test purpose.
+func (r *RegionStatistics) IsEmpty() bool {
+	r.RLock()
+	defer r.RUnlock()
+
+	return len(r.stats[MissPeer]) == 0 && len(r.stats[ExtraPeer]) == 0 && len(r.stats[DownPeer]) == 0 &&
+		len(r.stats[PendingPeer]) == 0 && len(r.stats[OfflinePeer]) == 0 && len(r.stats[LearnerPeer]) == 0 &&
+		len(r.stats[EmptyRegion]) == 0 && len(r.stats[OversizedRegion]) == 0 && len(r.stats[UndersizedRegion]) == 0
+}
+
 // Reset resets the metrics of the regions' status.
 func (r *RegionStatistics) Reset() {
 	regionStatusGauge.Reset()
 }
 
-// Clone clones the regions' status.
-func (r *RegionStatistics) Clone() *RegionStatistics {
-	r1 := &RegionStatistics{
-		stats: make(map[RegionStatisticType]map[uint64]*RegionInfo),
-	}
+// GetStats returns the regions' status.
+func (r *RegionStatistics) GetStats() map[RegionStatisticType]map[uint64]*RegionInfo {
+	r.RLock()
+	defer r.RUnlock()
+	stats := make(map[RegionStatisticType]map[uint64]*RegionInfo)
 
 	for _, typ := range statsTypes {
-		r1.stats[typ] = make(map[uint64]*RegionInfo)
+		stats[typ] = make(map[uint64]*RegionInfo)
 		for k, v := range r.stats[typ] {
-			r1.stats[typ][k] = v
+			stats[typ][k] = v
 		}
 	}
 
-	return r1
+	return stats
 }
 
 // LabelStatistics is the statistics of the level of labels.
@@ -307,6 +344,14 @@ func (l *LabelStatistics) Collect() {
 	}
 }
 
+// ResetStats resets the statistics.
+func (l *LabelStatistics) ResetStats() {
+	l.Lock()
+	defer l.Unlock()
+	l.regionLabelStats = make(map[uint64]string)
+	l.labelCounter = make(map[string]int)
+}
+
 // Reset resets the metrics of the label status.
 func (l *LabelStatistics) Reset() {
 	regionLabelLevelGauge.Reset()
diff --git a/tests/pdctl/region/region_test.go b/tests/pdctl/region/region_test.go
index 00146b9e1a15..dda8505c74a0 100644
--- a/tests/pdctl/region/region_test.go
+++ b/tests/pdctl/region/region_test.go
@@ -102,7 +102,7 @@ func TestRegion(t *testing.T) {
 	)
 	defer cluster.Destroy()
 	tu.Eventually(re, func() bool {
-		return leaderServer.GetRaftCluster().GetLastRegionStats() != nil
+		return !leaderServer.GetRaftCluster().IsLastRegionStatsEmpty()
 	})
 	var testRegionsCases = []struct {
 		args   []string