A drug test is a technical analysis of a biological specimen – for example urine, hair, blood, sweat, or oral fluid / saliva – to determine the presence or absence of specified parent drugs or their metabolites. Major uses of drug testing are to detect the presence of performance enhancing steroids in sport or for drugs prohibited by laws, such as cannabis, cocaine and heroin.The detection windows depend upon multiple factors – drug class,amount and frequency of use, metabolic rate, body mass, age, overall health, and urine pH.