Can an injection of a steroid the day before a blood lab is done affect results where Leukocytosis is recognized?

Yes, an injection of a steroid the day before a blood lab can affect results and may lead to leukocytosis, which is an elevated white blood cell count. Steroids can stimulate the bone marrow to produce more white blood cells and can also cause a redistribution of these cells from the marginal pool into circulation. This can result in misleading lab results that may not accurately reflect the individual's true health status. Therefore, it is important to inform the healthcare provider about recent steroid use before lab tests are conducted.