How are viral infections diagnosed?

Usually your doctor can diagnose a viral infection simply by noting your symptoms. Sore throat, coughing, and a runny nose are all commonly caused by viruses that infect your upper respiratory system. If there is a flu going around your doctor will note the symptoms that are common for that particular type of influenza and diagnose it based on those findings. Cultures may be taken from secretions, or your doctor might take a blood test to determine what type of virus has infected your body.