U00-U49: Provisional assignment of new diseases of uncertain etiology or emergency use

U23: Emergency use of U23

The U23 code in the ICD-10 WHO 2016 classification is designated for "Emergency use of U23." This group of conditions is reserved for health emergencies that have internationally widespread implications, such as the COVID-19 pandemic. These conditions are typically infectious diseases, which are transmitted from person to person, often through airborne particles or close personal contact. The symptoms associated with these conditions vary widely, depending on the specific disease, but may include fever, cough, trouble breathing, fatigue, and other flu-like symptoms. Disease progression also varies, but many of these conditions can cause serious, potentially life-threatening complications, especially in those with weakened immune systems or other underlying health issues. These conditions can affect many systems in the body, including respiratory, immune, and sometimes cardiovascular and nervous systems.