From the Guidelines
Dehydration can indeed cause an elevated White Blood Cell (WBC) count, known as pseudoleukocytosis or relative leukocytosis, due to hemoconcentration. This condition occurs when dehydration reduces blood plasma volume, but the number of white blood cells remains the same, resulting in a higher concentration of WBCs per volume of blood. Although the provided study 1 discusses dehydration in the context of diabetes management during Ramadan, it highlights the potential for dehydration to cause significant physiological changes, including orthostatic hypotension and electrolyte depletion.
In the context of WBC counts, dehydration leads to a mild to moderate elevation, which is not a true increase in white blood cell production but rather a measurement artifact. Other laboratory values like hemoglobin and hematocrit are often elevated simultaneously for the same reason. Key considerations for healthcare providers include:
- Hydration status when interpreting elevated WBC counts
- Presence of other signs of dehydration, such as increased blood urea nitrogen (BUN), elevated creatinine, or high urine specific gravity
- The need for rehydration with oral or intravenous fluids, depending on the severity of dehydration, to normalize the WBC count if dehydration is the primary cause of the elevation.
Given the potential for dehydration to impact laboratory results, including WBC counts, it is essential to consider a patient's hydration status in clinical practice, especially in scenarios where dehydration is likely or has been identified.
From the Research
Dehydration and White Blood Cell Count
- Dehydration can lead to an increase in white blood cell (WBC) count, as evidenced by a study on thermal dehydration, which found that WBC levels increased beyond what would be expected due to hemoconcentration alone 2.
- This increase in WBC count may be related to the body's response to dehydration, as dehydration can cause changes in blood composition and protein metabolism, similar to those seen with physical exercise 2.
- However, the exact mechanism by which dehydration affects WBC count is not fully understood and may involve complex interactions between various physiological processes.
Related Physiological Changes
- Dehydration can cause changes in red blood cell behavior, including alterations in viscoelastic properties and rigidity, which may contribute to the pathology of certain disorders 3.
- Dehydration can also lead to changes in serum protein fractions, with increases in globulin concentrations and no change in albumin levels 2.
- Additionally, dehydration can cause electrolyte imbalances, including elevated serum potassium levels 2, which may have implications for various physiological processes.
Clinical Implications
- In clinical settings, dehydration is often assessed through laboratory tests, including measurements of total serum protein, hematocrit, urea nitrogen concentration, and acid-base disturbances 4.
- White blood cell count is not typically used as a primary indicator of dehydration, but elevated WBC counts have been associated with increased risk of coronary heart disease and death in certain populations 5.