Common ailments are illnesses that many people suffer from. The most common ailments include the COLD, FLU, and headcold. The COLD is a viral infection of the upper respiratory system, which is characterized by a runny nose, sore throat, and coughing. The FLU is an infectious disease caused by the influenza virus, which is characterized by fever, chills, body aches, and fatigue. A headcold is an infection of the sinuses, which is characterized by a stuffy or runny nose, headache, and facial pain.