Final answer:
The common cold is caused by a virus, with rhinoviruses being a common type. These viruses infect the nasal cavities, leading to symptoms like a runny nose and sore throat. The condition is self-limiting and usually resolves within a couple of weeks, although factors such as smoking can worsen symptoms.
Step-by-step explanation:
The common cold is primarily caused by a virus. Viral infections of the upper respiratory tract are highly prevalent, with viruses such as rhinoviruses, coronaviruses, and adenoviruses being some of the main culprits. These viruses are adept at transmission through both direct contact and droplets spread by coughing and sneezing. This ease of spread is exacerbated by their ability to survive on surfaces for extended periods.
When a virus comes into contact with the nasal mucosa or eyes, it may lead to an infection. Rhinoviruses are particularly noteworthy as they replicate optimally at temperatures slightly below normal body temperature, favoring the cooler environment of the nasal passages. The immune response to the invading virus manifests as the symptoms we recognize as a cold, including runny nose, sore throat, and coughing. Unlike bacterial infections, which can be treated with antibiotics, viral infections require supportive care, as their self-limiting nature means they generally resolve within one to two weeks. However, individuals who smoke, like Sacheen in the case study, may experience worse symptoms due to the irritation caused by tobacco on the respiratory mucosa.
Infection outcomes can vary based on the virulence of the virus and the individual's immune system. While most infections lead to mild symptoms, in some cases, complications such as otitis media can occur. It is important to recognize that the color of nasal secretions does not necessarily indicate the type of pathogen causing the infection.