What are signs and symptoms of the flu versus the common cold?

Overlap but severity: Most people have frequent "cold" which are usually caused by rhinovirus, adenoviruses and others small viruses - the body usually confines these to the upper respiratory tract and usually fights them off in 2-5 days. Over 5-10 days the flu can spread down into the lungs, causes high fevers, muscle pain, joint pain and more rarely lead to severe pneumonia requiring ventilator support and death.