Urinalysis refers to a group of tests conducted on urine sample to determine the various chemical components of the urine. Urine analysis is an examination of the urine sample that gives useful information regarding the renal and metabolic disorders, kidney or urinary tract infections, diabetes and host of other diseases. Urinalysis does not diagnose the disease itself, rather the presence of abnormal substances in the urine that will help direct the course of further evaluation and diagnosis. Depending upon the symptoms reported, urinalysis is conducted in three different phases.
1. Visual analysis or physical examination
2. Chemical analysis
3. Microscopic analysis
Physical examination of urine
Color: Normally urine looks pale yellow; any change in the color of the urine indicates some abnormality, for example dark yellow urine indicates dehydration whereas bile pigments cause brown urine. Urine turns red when there is blood in the urine. Sometimes consumption of certain foods such as blackberries, rhubarb and beets turns the urine red.
Clarity: Normal urine is usually clear, cloudy urine indicates the presence of bacteria, blood, sperm, crystals, or mucus. Odor: Normal urine has a nutty odor to it whereas diabetes gives urine a fruity odor and bacterial infections lead to bad odor of the urine.
Chemical analysis of urine
Chemical examination is normally conducted with the help of the dipstick. The change in the colors of the different pads on the dipstick indicates varied health conditions.
pH balance: pH balance measures the acidic and alkaline balance of the urine. The lower or higher pH indicates kidney disorders. pH balance can be changed by consuming the appropriate diet.
Protein: Protein test normally involves examining the albumin levels in the urine. The elevated albumin level is the initial symptom of kidney disorder.
Glucose: Higher glucose levels in the urine is associated with diabetes and other conditions like hormonal disorders, liver disease and pregnancy.
Ketones: When the body does not get enough carbohydrates, it starts metabolizing the fats to gather energy and in process releases ketones into the urine, thus indicating the low levels of insulin.
Blood: Urine is also tested for the presence of red blood cells. Various kidney and urinary tract diseases and trauma, injury, medications, smoking, or strenuous exercise lead to the contamination of urine with the blood.
Nitrites: UTI or urinary tract infection changes the urinary nitrates into nitrites. Therefore the presence of nitrites indicates the presence of UTI. Likewise urine is also tested for Leukocytes as they too indicate the presence of UTI.
Microscopic urine analysis
This test involves collection of urine in centrifuge to be spun for few minutes, so that sediments settle at the bottom. The sediment substance is then spread on the slide and examined under microscope. The urine is tested for the following:
If the urine shows red or white blood cells, it signals an inflammation, kidney disease or an injury of the ureters, bladder, or urethra. Microscopic examination of urine also reveals the presence of crystals. Large number of Crystals in the urine indicates dehydration, pH imbalance, UTI or a condition called Urolithiasis, signifying kidney stone or bladder stones. Urine is also tested for bacteria, yeast cells, or parasites, as any of these organisms in the urine signals infection. Increased quantity of epithelial cells in urine could indicate some health problems.
Ureteroscopy is a common urological procedure administered in patients having urinary tract and bladder related disorders. Ureteroscopy is recommended for patients having kidney stones. The movement of the renal stones is monitored by urologists. Ureteroscopy is a minimal invasive endoscopic procedure predominantly involving the urethra, upper urinary tract and the urinary bladder.
A flexible or rigid form of telescope is passed through the urethra in order to view the affected region. The procedure is performed under general or spinal anesthesia. The telescopic examination of the ureter and associated organs reveals the exact location of the stone and also other disorders of the system. Other diagnostic tests such as X-rays, CT scan, EKG along with laboratory parameters like urinalysis and complete blood count also help in the effective determination of the underlying condition. This technique is usually followed by the other associated procedures such as lithotripsy in which laser beams are administered to the affected region to dissolve the calculi(stone) or to clear urinary tract strictures. The entire procedure may last from 30 minutes to three hours and patients are advised to stay in the hospital for a day.
The urologist uses the uterescope to remove small kidney stones while larger stones need to be broken up before removal. A kidney stone that has escaped from the kidney and got stuck in the ureter can be pushed back into the kidney. Here it has to be broken into smaller pieces to aid removal. A stent is usually left in place to allow the kidneys to pass the urine to the bladder. This is kept for a few days in case there is swelling and subsequent difficulty in draining the kidney of the urine.
Complications and risk factors
Hematuria happens because of the insertion of the ureteroscope. It usually subsides within 3 days. Antimicrobial therapy is given if hematuria is followed by an infection. Other possible complications are:
Stent associated pain
Perforations caused because of stents
Lower back pain
Urethral stricture or perforation
The medical term for cloudy, frothy and foul smelling pus in the urine is pyuria. It means the presence of significantly elevated level of white blood cells (leukocytes) in urine. White blood cells work with the immune system to defend against infectious diseases. A small number of white blood cells are normally present in the urine. But elevated levels indicate urinary tract problems signaling possible damage to the kidneys, ureters, urethra or bladder, inflammation or a contaminant.
Pyuria can be symptomatic or asymptomatic. Pyuria due to bacterial infection is symptomatic unless partially treated. Pyuria is asymptomatic when related to chronic infection from tuberculosis or mycoplasma, long-time indwelling catheters, inflammatory conditions like hemorrhagic cystitis, tubulointerstital nephritis or chronic prostatitis in men, or a contaminant such as vaginal secretions, vaginitis, cystocele etc. Asymptomatic pyuria goes away on its own, even without treatment.
Time to test
The test is done when individuals notice symptoms and seek medical attention. A physical examination is followed by laboratory urine test for pyuria urinalysis. If the test indicates pyuria, a culture of urine is suggested to detect the strain of bacteria that causes pyuria. To detect kidney abnormalities or infection, an intravenous pyelogram or ultrasound imaging of kidney is done. The presence of more than 3-5 white blood cells per high power field in the spun urine confirms pyuria.
Urinary tract infection: The chance of urinary tract infection is high in men and women who are diabetic. As the urethra in women is comparatively shorter than men, it is easier for microorganisms to enter the female urinary tract and cause infection which increases the chance of women contracting urinary tract infection.
Sexually transmitted diseases: Men and women with sexually transmitted diseases are prone to pyuria.
Other causes: Other causes can be infectious or non-infectious.
Non infectious: Medications, advanced age, pregnancy, tumors either benign or malignant can cause pus in the urine. Any other underlying problem in the kidney can also result in excessive levels of white cells in the urine.
The cause for pyuria determines treatment. For urinary tract infections, doctors prescribe antibiotic medicines. If the cause is due to sexually transmitted diseases, hygiene and other precautionary measures is recommended. Drinking plenty of water, juices sans sugar, avoiding fried foods, practicing good hygiene, not delaying for too long the urgency to urinate are proven precautionary measures of pyuria.
Bibliography / Reference
Collection of Pages - Last revised Date: March 21, 2019