Conditions favorable to population screening for symptomatic diagnosis includes a relatively high prevalence of disease, availability of effective treatment, a screening test with high sensitivity and the presence of a physician that can perform the test. Screening is a technique used in population to detect presence of not yet diagnosed disease in individuals without having signs or symptoms. They are several types of this screening such as universal screening,case findings and others. There are several principles employed by the WHO as a guidelines for practice of screening for diseases. Commonly, there are various programmes employed for screening diseases such as cancer screening, PPd test, screening for metabolic diseases and others.