Symptoms, vital signs, laboratory values and BIA (Bio Impedance Analysis) measurements are tracked. The way a BIA machine works is similar to that of an EKG. The BIA measures reactance (related to the ability of the cell to store charge, and variations can occur depending on its integrity, function and composition) and resistance (opposition offered by the body to the flow of an alternating current. Water and electrolytes have lower resistance, fat has higher resistance). 

Computer regression analysis of reactance and resistance gives computed data such as proportions of intracellular water, extracellular water, body cell mass (skeletal muscle, smooth muscle, organ tissue), free fat mass, phase angle, basal metabolic rate; when parameters such as age, weight, height, amount of exercise are entered into the program. BIA devices are required by the NIH to be standardized and results are accurate and reproducible.