In the Resource Guide it indicates that it’s a condition. However, the Condition resource says the following
This resource is not typically used to record information about subjective and objective information that might lead to the recording of a Condition resource. Such signs and symptoms are typically captured using the Observation resource
Where do you typically store subjective information such as Chief Complaints, History of Present Illness etc?
Something being a ‘chief complaint’ or ‘history of present illness’ are actually relationships between a Condition and an Encounter. The same Condition might be a chief complaint for multiple encounters, but only part of the history for others. The Encounter.diagnosis.use helps differentiate.
Whether you choose to represent something as a Condition or an Observation sort of depends on what it is. However, there is a fuzzy boundary. Sometimes ‘pain’ is an Observation. Sometimes it’s worth elevating to a Condition as something a clinician wants to track and manage over time.