Would you believe there are actual medical conditions called Christmas Disease, Nutcracker Syndrome, and Grinch Syndrome? We promise, we\u2019re not being naughty and making it up.\nAlthough they\u2019re rare, these conditions are real, and they affect the blood, heart, and blood vessels, causing serious symptoms like pain, bleeding, and fainting. Find out more about these disorders below.\n\nWhat is Hemophilia B (Christmas Disease)?\nHemophilia B, also known as \u201cChristmas Disease,\u201d is a rare genetic disorder that does not allow blood to properly clot due to insufficient levels of blood protein called Factor IX. This is the second most common type of hemophilia.\nWhat is Nutcracker Syndrome?\nNutcracker Syndrome is a vascular compression disorder where the vein from your kidneys is pinched between your aorta and another smaller artery in your abdomen. Symptoms of nutcracker syndrome include blood in urine and left flank pain.\nWhat is Postural Orthostatic Tachycardia Syndrome (POTS or Grinch Syndrome)?\nPostural orthostatic tachycardia syndrome (POTS), also referred to as \u201cGrinch Syndrome,\u201d causes a rapid increase in heartbeat when standing up from a lying position. Many times this is accompanied by light-headedness and dizziness. Most patients have small hearts; POTS affects about 500,000 Americans, primarily young women.\nConcerned you\u2019re exhibiting symptoms of one of these conditions? Contact your primary care physician or visit the UPMC Heart and Vascular Institute website for more information on treatment options.