Systems and methods for diagnosing one or more respiration distress manifestations by implantably recognizing their occurrence and evaluating information about the same to provide an indication of present or impending worsening heart failure are discussed. Using information produced by an implantable respiration sensor circuit and an implantable physiological sensor circuit, such as at least one of a physical activity sensor circuit or a posture sensor circuit, an implantable or external processor circuit may detect a respiration disturbance and an associated subsequent arousal from stable state occurrence and thereafter evaluate over time arousal from stable state occurrences to provide the indication of present or impending worsening heart failure. In one example, information about a fluid level within a subject is used in determining the indication of worsening heart failure. In various examples, a regimen is initiated or adjusted in response to the indication of present or impending worsening heart failure.