Dipstick reagents are primarily used as screening tools for components in the urine such as protein, blood, bilirubin, glucose, ketones, nitrites and leucocyte esterase, which can be indicators of bacterial infection; it is also used to check the urine's pH (Provan [167]).

A urine dipstick is usually a narrow plastic strip that has several different coloured squares on it, each representing the components described above, impregnated with chemicals (Provan [167]). When dipped in urine, the chemicals react with abnormal substances and change colour (Marini and Dries [112]). Once the strip has been quickly dipped into the urine sample and the necessary time has lapsed for the colour changes to take place, the strip is compared to a standardized colour chart that displays results in terms of parameters (Tait et al. [194]). It is essential to use the strips according to the manufacturer's instructions and be aware of factors that may affect their results, including specific drugs (see Table 14.13), the quality of the urine specimen itself and the possibility of false‐negative results (Marini and Dries [112]).

Most patients need advice on hygiene and technique before collecting a urine sample to prevent contamination from hands or the genital area and to ensure that the midstream sample is collected correctly (Holm and Aabenhus [84]).