While progress has been made toward understanding physical and mental fatigue, chronic fatigue has been under-studied and stigmatized. Unlike other fatigue states that can be relieved by rest, chronic fatigue is a common, debilitating symptom of many chronic conditions. Utilizing deidentified patient data from the Yale-New Haven Hospital System, we analyzed the overlap between diagnosed fatigue and 14 chronic conditions. Our results revealed a significantly lower overlap with fatigue than previous reports in all but one of the current diagnoses’ fields. The underreporting of disabling fatigue across chronic conditions restricts the translation between medical and basic scientific research. Accurate reporting of the prevalence of chronic fatigue can result in researchers refocusing their efforts toward uncovering targetable mechanisms and physicians consistently reporting and treating chronic fatigue.

The authors have declared no competing interest.

This study did not receive any funding.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Yale IRB determined that the investigator is not engaged in research involving human subjects. As such, IRB review and approval are not required.

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All data produced in the present work are contained in the manuscript.