PNH (paroxysmal nocturnal hemoglobinuria) is a rare illness that is potentially deadly. It can turn a patient's urine red in the morning, lead to anemia, form dangerous blood clots, and lead to a stroke. It can also cause Budd-Chiari syndrome, which is a blockage of the vein that leads blood away from the liver. USS (undifferentiated seronegative spondyloarthropathy) is a rare illness that affects the vertebral column. It can cause inflammation of the eyes, 'locking' of joints to where you can't move them, lower back pain, and many other symptoms.