A doctor determines the total amount of samples taken for laboratory tests. The laboratory analysis is then a source of information, which can be used for evaluating a patient's health condition. Blood analysis provides a number of important data for determining or specifying a diagnosis, choice of correct method of treatment as well as following its course and finding prognostic or risk factors. Blood samples are performed by the specialised medical staff. A client must have an empty stomach before the samples are taken. The results of laboratory analysis are later appraised by a doctor, who then suggests a method of treating non-standard values.