The systemic symptoms of influenza are more pronounced and differ from those of the common cold. The main symptoms are fever, body aches, headache, palpitations, and cough. Severe fever, often with high body temperature, or persistent fever as well as intermittent fever, and common symptoms include pharyngeal congestion, conjunctival congestion, and swollen lymph nodes in the neck. In adults, the resolution of fever and systemic symptoms usually takes 3-5 days, but upper respiratory symptoms, including dry cough and chest pain, gradually increase. Acute flu-like symptoms in the elderly are characterized by depression and unresponsiveness. Recovery from influenza, such as cough and malaise, is also slow and usually lasts for 2-4 weeks, which may be related to malaise as well as decreased endurance of the patient during the recovery period.