system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the cold virus always seem to progress through the same stages of symptoms in the same order? (sore throat - sneezing - congestion - runny nose - cough) Also, what is the cold virus actually doing during each stage?

My girl friend and I always get the same symptoms in the same order. However, she travels through each set of symptoms very quickly. (2-3 days total) It takes me 2 weeks to progress through the stages. 

Why does she get to the cough stage in 2 days, while my body takes over a week? Assuming my immune system is compromised (because the cold takes longer to heal) shouldn't I get to the cough stage in 2 days as well or even sooner?
gpt
The "cold virus" is just a term for any virus that causes mild respiratory illness.  The majority of cold symptoms are actually caused by your body's response to viral replication.  What you experience in a cold is less an issue of what the virus is doing and more an issue of how your body's response starts, progresses, and resolves.

When your body detects a viral invader, it mounts a rapid, nonspecific response.  You get inflammation (redness, pain, swelling, fever) and an antiviral response from interferon production (more fever, muscle aches, fatigue, and generally feeling lousy).  Since the infection is occurring on surfaces in the upper respiratory tract, there is also increased mucus production.  The inflammatory response irritates tissues, and together with mucus can cause congestion, coughing, and sneezing.

These responses are shaped by genetic factors.  Not everyone experiences the exact same symptoms for the same duration in the same order.  Also, you are not necessarily symptomatic longer because your immune system is compromised.  Your immune response takes longer to resolve.  In some cases, the overzealous responses of "healthy" immune systems can increase the duration or severity of disease.