"Multiple tests are available to check for malignant hyperthermia, including genetic testing, caffeine halothane contracture test that involves a fresh muscle biopsy, and calcium induced release tests that involve an intramuscular injection. Negative tests unfortunately do not completely rule out malignant hyperthermia. That's why anyone with even a vague family history of malignant hyperthermia will always be treated as a malignant hyperthermia patient, which means you will not receive any triggering agents during anesthesia. If the pre-anesthesia assessment alludes to a family history of malignant hyperthermia, or the patient has a history, the patient will be treated preventively, which means no triggering agents will be administered. If malignant hyperthermia is suspected during general anesthesia, malignant hyperthermia will be treated immediately and proactively. Besides supportive treatment, there are very effective medications that can be given when malignant hyperthermia is suspected. Symptoms of malignant hyperthermia usually occur during the administration of general anesthesia, however, can appear up to 24 hours after undergoing anesthesia with malignant hyperthermia triggering agents. Although symptoms will be treated immediately, side effects from malignant hyperthermia might last for days to weeks and can be permanent. Patients should always tell all physicians involved in their care if there's a family history or personal history of malignant hyperthermia. It is vital that the entire care team knows about this history. As an example, if you have an uncle that had malignant hyperthermia and you're scheduled for your first surgery, your uncle's history tells your anesthesiologist that you are high risk, therefore you will automatically be treated as a malignant hyperthermia susceptible patient. Your anesthesiologist will take all necessary precautions and you will not receive any malignant hyperthermia triggering agents."