This is an illness caused by a viral infection, and there is no cure for it. Symptoms can include coughing, runny or stuffy nose, sore throat, or mild headaches. What is the illness?

The illness described in the question is the common cold, which is indeed caused by a viral infection and is characterized by symptoms such as coughing, a runny or stuffy nose, a sore throat, and mild headaches. Unlike tuberculosis, pneumonia, or hepatitis C, the common cold is a self-limited condition, meaning it usually resolves on its own without the need for specific medical treatment. There is no definitive cure for a viral infection like the common cold; instead, management often focuses on relieving symptoms until the body's immune system can effectively combat the virus. This understanding of the common cold's nature and symptomatology aligns with the details provided in the question.