diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index cf82a2336..7ae05603f 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -52,6 +52,8 @@ bump_active_time_counter = metrics.register_counter("bump_active_time")
 
 get_updates_counter = metrics.register_counter("get_updates", labels=["type"])
 
+notify_reason_counter = metrics.register_counter("notify_reason", labels=["reason"])
+
 
 # If a user was last active in the last LAST_ACTIVE_GRANULARITY, consider them
 # "currently_active"
@@ -940,26 +942,32 @@ def should_notify(old_state, new_state):
     """Decides if a presence state change should be sent to interested parties.
     """
     if old_state.status_msg != new_state.status_msg:
+        notify_reason_counter.inc("status_msg_change")
         return True
 
     if old_state.state == PresenceState.ONLINE:
         if new_state.state != PresenceState.ONLINE:
             # Always notify for online -> anything
+            notify_reason_counter.inc("online_to_not")
             return True
 
         if new_state.currently_active != old_state.currently_active:
+            notify_reason_counter.inc("current_active_change")
             return True
 
         if new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY:
             # Only notify about last active bumps if we're not currently acive
             if not (old_state.currently_active and new_state.currently_active):
+                notify_reason_counter.inc("last_active_change")
                 return True
 
     elif new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY:
         # Always notify for a transition where last active gets bumped.
+        notify_reason_counter.inc("last_active_change")
         return True
 
     if old_state.state != new_state.state:
+        notify_reason_counter.inc("state_change")
         return True
 
     return False