The part of the human body most affected by the common cold is the upper respiratory tract, which includes the nose and throat. The common cold, primarily caused by rhinoviruses, leads to symptoms such as congestion, sore throat, runny nose, and sneezing. These symptoms arise as the body’s immune system responds to the viral infection, resulting in inflammation of the affected areas. While most cases resolve without serious complications, colds can lead to secondary infections or exacerbate existing respiratory conditions, particularly in vulnerable populations like the elderly or those with asthma. Practicing good hygiene and rest can help in recovery.