Urinalysis is the analysis of a person’s urine to detect things such as drugs and infections. A person is asked to produce a urine sample; sometimes this will be a mid-stream urine sample to ensure the cleanest possible sample is caught.
First off, the physical characteristic of the urine, such as colour, concentration and cloudiness will be noted. A urine dipstick will then be used to give a rough idea of the properties of the urine, such as the acidity; concentration; presence of glucose (which can be used to monitor the treatment of diabetes mellitus); the presence of blood; protein; white blood cells; and bile. A pregnancy test is a form of urinalysis that detects the presence of human chorionic gonadotrophin (hCG) which is a hormone secreted by the embryo.
The urine sample can then be sent off to a lab for further testing. Here they can perform further, more sensitive chemical tests to detect drug levels (such as for drug testing in athletes). The lab is also able to culture the urine to see if there is are bacteria present that are causing a urinary tract infection; a small drop of the urine is placed on the surface of a nutrient gel. Any bacteria present will grow colonies that can be identified by a microbiologist.
A drop of urine is also placed on a slide and looked at under a microscope. Things that can be seen include red blood cells (haematuria) which indicate possible kidney damage, fragments of proteins and kidney cells, pus (from infection), and crystals (which can indicate a metabolic illness). The eggs of the schistosomiasis parasite can be also identified by using a microscope.