Rare genetic condition where certain anesthetic drugs, and sometimes exercise or hot environments can trigger life-threatening oxidative changes.Encyclopedia Entry for Malignant Hyperthermia :Malignant hyperthermia. MH is inherited. Only one parent has to carry the disease for a child to inherit the condition. It may occur with some other inherited muscle diseases, such as multiminicore myopathy and central core disease.Symptoms of MH include: Bleeding Dark brown urine Muscle ache without an obvious cause, such as exercise or injury Muscle rigidity and stiffness Rise in body temperature to 105 F (40.6 C) or higher.MH is often discovered after a person is given anesthesia during surgery. There may be a family history of MH or unexplained death during anesthesia. The person may have a fast and often irregular heart rate. Tests for MH may include: Blood clotting studies (PT, or prothombin time ; PTT, or partial thrombloplastin time ) Blood chemistry panel, including CPK (creatinine phosphokinase, which is higher in the blood when muscle is destroyed during a bout of the illness) Genetic testing to look for defects in the genes that are linked with the disease Muscle biopsy Urine myoglobin (muscle protein).During an episode of MH, a medicine called dantrolene is often given. Wrapping the person in a cooling blanket can help reduce fever and the risk of serious complications. To preserve kidney function during an episode, the person may receive fluids through a vein.These resources can provide more information about MH: Malignant Hyperthermia Association of the United States -- www.mhaus.org National Organization for Rare Disorders -- rarediseases.org/rare-diseases/malignant-hyperthermia NIH Genetics Home Reference -- ghr.nlm.nih.gov/condition/malignant-hyperthermia.Repeated or untreated episodes can cause kidney failure. Untreated episodes can be fatal.These serious complications can occur: Amputation Breakdown of muscle tissue Swelling of the hands and feet and problems with blood flow and nerve function ( compartment syndrome ) Death Abnormal blood clotting and bleeding Heart rhythm problems Kidney failure Buildup of acid in the body fluids ( metabolic acidosis ) Fluid buildup in the lungs Weak or deformed muscles (myopathy or muscular dystrophy ).If you need surgery, tell both your surgeon and anesthesiologist before surgery if: You know that you or a member of your family has had problems with general anesthesia You know you have a family history of MH Using certain medicines can prevent the complications of MH during surgery.Tell your health care provider if you or anyone in your family has MH, especially before having surgery with general anesthesia. Avoid stimulant drugs such as cocaine, amphetamine (speed), and ecstasy. These drugs may cause problems similar to MH in people who are prone to this condition. Genetic counseling is recommended for anyone with a family history of myopathy, muscular dystrophy, or MH.Hyperthermia - malignant; Hyperpyrexia - malignant; MH.American Association of Nurse Anesthetists. Malignant hyperthermia crisis preparedness and treatment: position statement. sharepoint.aana.com/resources2/professionalpractice/Pages/Malignant-Hyperthermia-Crisis-Preparedness-and-Treatment.aspx. Updated April 2015. Accessed June 8, 2017. Kulaylat MN, Dayton MT. Surgical complications.