R00-R09: Symptoms and signs involving the circulatory and respiratory systems

The group of conditions represented by the ICD-10 R00-R09 pertains to symptoms and signs involving the circulatory and respiratory systems. These are not full-fledged illnesses in their own right, but rather symptoms or signs that could point towards a variety of different diseases. Conditions in this group affect either the heart and blood vessels (circulatory system), or the lungs and airways (respiratory system). Common symptoms may include chest pain, cough, shortness of breath, abnormal heart rhythms, and unusual sounds heard via stethoscope examination. Diseases can be present from birth (congenital) or may develop over time due to lifestyle factors, exposure to harmful substances, or infections. Disease progression and severity can widely vary from mild and asymptomatic to severe and life-threatening. Therefore, effective diagnosis and management largely depend on the underlying disease the symptoms indicate.