When I was first diagnosed with thyroid cancer, I didn't feel any odd lumps or nodules in my neck, but I was suffering from muscle weakness, tiredness and getting constant colds. After a particularly nasty bug I noticed that my lymph nodes never seemed to go down in size.
SIRS is nonspecific and can be caused by ischemia, inflammation, trauma, infection, or several insults combined. Thus, SIRS is not always related to infection. Venn diagram showing overlap of infection, bacteremia, sepsis, systemic inflammatory response syndrome (SIRS), and multiorgan dysfunction.
SIRS is a clinical response to a non-specific insult which may be either infectious or non-infectious in etiology. When evaluating a patient with SIRS, a careful history, physical and laboratory evaluation is critical for identifying the cause and will impact initial therapy.