A diagnostic health system comprising: a patient-specific device selected from the group consisting of a wearable device and an implantable device; and an external breath sensing system; and a processor configured to receive data from the patient-specific device and the external breath sensing system; wherein the patient-specific device is configured to collect data regarding a patient's sympathetic nervous activity; wherein the external breath sensing system is configured to collect data regarding the presence of volatile organic compounds in a breath or gas sample of the patient; and wherein the system is configured to download volatile organic compound data from a breath sample of the patient onto the patient-specific device from the external breath sensing system, wherein the processor is configured to combine the volatile organic compound data with the patient's sympathetic nervous activity data to form a combined data set; and match the combined data set against one or more previously determined data patterns using a pattern matching algorithm to determine a pattern that is the best match, wherein the specific previously determined pattern that is the best match indicates the health status of the patient; and report the health status of the patient based on the best pattern match. wherein the processor is receiving data from the patient-specific device and the breath sensing system, the breath sensing system being an external breath sensing system; wherein the patient-specific device collects the data regarding a patient's sympathetic nervous activity; wherein the external breath sensing system collects data regarding the presence of volatile organic compounds in a breath or gas sample of the patient. a patient-specific device selected from the group consisting of a wearable device and an implantable device; and an external breath sensing system; and a processor configured to receive data from the patient-specific device and the external breath sensing system; wherein the patient-specific device is configured to collect data regarding a patient's sympathetic nervous activity; wherein the external breath sensing system is configured to collect data regarding the presence of volatile organic compounds in a breath or gas sample of the patient; and wherein the system is configured to download volatile organic compound data from a breath sample of the patient onto the patient-specific device from the external breath sensing system, wherein the processor is configured to combine the volatile organic compound data with the patient's sympathetic nervous activity data to form a combined data set; and match the combined data set against one or more previously determined data patterns using a pattern matching algorithm to determine a pattern that is the best match, wherein the specific previously determined pattern that is the best match indicates the health status of the patient; and report the health status of the patient based on the best pattern match. wherein the processor is receiving data from the patient-specific device and the breath sensing system, the breath sensing system being an external breath sensing system; wherein the patient-specific device collects the data regarding a patient's sympathetic nervous activity; wherein the external breath sensing system collects data regarding the presence of volatile organic compounds in a breath or gas sample of the patient.