Clinical features refer to the signs and symptoms that characterize a particular disease or medical condition in a patient. These features can include physical symptoms such as pain, fever, rash, or weakness, as well as psychological symptoms like mood changes or cognitive difficulties. Clinicians use these features to aid in the diagnosis and treatment of patients, as they provide valuable information about the underlying cause of the patient's illness. In medical research, studying the clinical features of a disease can help researchers understand its progression, identify risk factors, and develop better treatment strategies.