Abstract: A noninvasive blood chemistry measurement method and system isolate measurement contributions due to a patient's blood to accurately measure blood chemistry. In accordance with a first preferred embodiment of the present invention a noninvasive blood chemistry measurement method decreases the blood volume within a patient's body part relative to the normal blood volume in the body part and performs a baseline measurement. Blood volume is then increased and a second measurement is performed. Comparison of the second measurement to the baseline measurement isolates the measurement attributes of the patient's blood. In accordance with a second preferred embodiment of the present invention a noninvasive blood chemistry measurement system decreases blood volume by applying mechanical pressure to a body part. In accordance with a third preferred embodiment of the present invention, blood volume in the body part is decreased using a pressure cuff.