Cryofibrinogenemia is a rare blood disorder in which there is a certain abnormal protein called cryofibrinogen present in the blood. In most cases, individuals experience no symptoms. However in more moderate to serious cases, symptoms can include skin lesions, red or purple marks (purpura), poor blood circulation, stroke, heart attack, blood clots, and extra sensitivity to cold. It is currently unclear what causes cryofibrinogenemia, but it is sometimes associated with certain cancers and infections such as strep, tuberculosis, hepatitis C and others. A simple blood test is usually conducted to diagnose this condition, and sometimes skin biopsies may be needed. Additional testing may be needed to determine if there is an underlying cause such as cancer or infection. Cryofibrinogenemia is treatable and potentially reversible through corticosteroid drugs. People affected with this condition should also avoid extremely cold temperatures. If you or a family member has been diagnosed with cryofibrinogenemia, talk with your doctor about the most current treatment options.