A typical viral cold or mild throat infection is most likely the cause of your symptoms, which include runny nose, cough, sore throat, and light headache without fever. To reduce nasal obstruction and throat discomfort, try steam inhalation two to three times a day, drink warm water and fluids, stay away from cold beverages and greasy foods, and get enough of rest. Gargling with warm salt water can also help relieve sore throats. If taken as directed by a physician or pharmacist, simple medications like paracetamol for headaches and cough or cold remedies may be beneficial. If symptoms persist for more than a week, breathing becomes difficult, coughing becomes severe, or fever develops later, please consult a physician.