The work of the clinical laboratory professional - who analyzes chemical indicators in the body to provide the doctor with a clearer picture of a patient's health - has long been an unseen aspect of health care. Yet, clinical lab tests often provide the link between the patient's presentation of symptoms and the doctor's diagnosis of and prescribed treatment for a particular condition or disease. Through preventative screening, laboratory tests also aid in the early detection of potentially fatal conditions, and in so doing, lead to early treatment. In short, lab tests can help both to save lives and to improve the quality of life.