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Understanding Symptoms

A pathologist explains the uncomfortable signs of illness.

Woman sick with flu rests on her couch.

Bedridden with fever, sore throat, stuffy nose, cough and fatigue? What is going on and why do you feel so awful?

Dr. Leilani Valdes, Medical Director at Regional Pathology Associates and Chair of Pathology and Laboratory Medicine at Citizens Medical Center in Victoria, Texas explains that those experiences being felt are known as symptoms – your body’s way of telling you it’s fighting off a pathogen.

“Viral particles trigger the body to say, ‘this is not normal, these proteins aren’t my own’ which sparks an inflammatory response to try and clear out the virus,” Valdes said. “And what a patient feels has directly to do with which cells the virus prefers to replicate in and your body’s response to the process of infection.”

Take influenza viruses, for example – these viruses typically replicate within the mucosal cells of the respiratory system, which is why symptoms like sore throat, congestion and a cough may develop, she said. If you’ve noticed feeling worse at night or in the morning, that could be due to fluctuations in hormones, like cortisol, which helps regulate the body’s inflammatory response.

“Your daily cortisol, the ‘fight or flight’ hormone, helps the body respond to the infection. In addition, you're probably hydrating and doing all the things during the day that you should do to help your body fight off the virus,” she said. “In the morning, your cortisol level starts increasing so you can get through the day. Then towards the end of the day, you’ve depleted your cortisol and possibly fell off your ‘feel better’ regimen of hydration and you're ready to have a little rest again.” 

Depending on the virus and how much it stimulates an individual’s response, the person will have symptoms that vary in severity. 

“A fever is going to be one of those ways the body tries to attack the invading virus,” Valdes said. “But sometimes your body overdoes it. That’s when physicians get worried because if your body triggers too much of an inflammatory response that can have other sequelae or complications, especially if you have underlying health conditions.”

You want your body to respond with the appropriate measures to fight the illness and “that is why vaccines are great because they prime the immune response so that you already have antibodies circulating and ready to fight,” she said. 

She explained that the benefit of vaccines, especially for a virus like influenza that’s mutating all the time, is that “you can nip the infection in the bud, so to speak, rather than have to start from the beginning. The circulating antibodies generated from having the vaccine may lead to fewer symptoms because the immune system does not need to incapacitate the infection on its own.”