A UA test, short for urinalysis, is a common lab test that examines your urine for signs of infection, kidney problems, diabetes, and other health conditions. It’s one of the most frequently ordered medical tests, and it can reveal a surprising amount about what’s happening inside your body. A single sample gets evaluated three different ways: a visual check, a chemical dipstick test, and sometimes a look under the microscope.
Why Doctors Order a Urinalysis
A urinalysis serves multiple purposes. It’s used as a routine screening during checkups and hospital admissions, as a diagnostic tool when symptoms like painful urination or back pain suggest a problem, and as a monitoring test for ongoing conditions like kidney disease or diabetes. If you’re pregnant, you’ll likely have your urine tested at most prenatal visits. It’s quick, non-invasive, and inexpensive, which is why it shows up so often in medical care.
The Three Parts of the Test
Visual Exam
A lab technician starts by simply looking at the sample. Normal urine is clear and pale to deep yellow. Cloudiness or an unusual odor can point to infection. Foamy urine sometimes indicates protein is present, which can signal kidney trouble. Red or brown urine may mean blood is in the sample, though certain foods like beets can also cause color changes.
Dipstick Test
This is where most of the information comes from. A thin plastic strip treated with chemical pads gets dipped into your urine. Each pad changes color based on what it detects, and the technician compares those colors to a reference chart. The dipstick checks for:
- pH (acidity): Normal urine pH ranges from 4.6 to 8, with an average around 6. Values outside this range can suggest kidney stones, urinary infections, or metabolic issues.
- Specific gravity (concentration): This measures how diluted or concentrated your urine is. Normal falls between 1.005 and 1.030. After drinking large amounts of water, it can drop as low as 1.001. After avoiding fluids, it rises above 1.030. This helps assess hydration and kidney function.
- Protein: Healthy urine contains very little protein. Elevated levels, called proteinuria, are one of the earliest signs of kidney damage. Guidelines grade it from normal (category A1) to severely increased (category A3), and persistent protein in your urine typically prompts further kidney testing.
- Glucose (sugar): Sugar in urine is normally undetectable. When it shows up, it usually means blood sugar levels have been high enough that the kidneys can’t reabsorb all the glucose, which is a hallmark of uncontrolled diabetes.
- Ketones: These shouldn’t appear in urine at all under normal circumstances. Ketones are produced when the body burns fat instead of sugar for energy. Any amount detected could point toward diabetes, prolonged fasting, or very low-carb diets. In someone with diabetes, ketones in the urine can be an early warning sign of a dangerous complication called diabetic ketoacidosis.
- Bilirubin: This is a byproduct of red blood cell breakdown, normally processed by your liver. Finding it in urine can indicate liver disease or bile duct problems.
- Infection markers: The dipstick looks for two key signs of urinary tract infection. Nitrites appear when certain bacteria convert natural compounds in urine. Leukocyte esterase is a substance released by white blood cells fighting an infection. Either one showing up suggests a UTI and usually leads to a urine culture for confirmation.
- Blood: Even tiny amounts of blood invisible to the naked eye (called microscopic hematuria) can be picked up by the dipstick. This always triggers additional testing to rule out causes ranging from kidney stones to bladder issues.
Microscopic Exam
If the dipstick results are abnormal, the lab may spin down a portion of your urine in a centrifuge and examine the sediment under a microscope. This step looks for things the chemical test can’t identify precisely. White blood cells in the sediment confirm an active infection or inflammation. Red blood cells point toward kidney disease, a blood disorder, or other conditions. Bacteria, yeast, or parasites visible under the microscope further confirm infection.
Two other findings are worth noting. Casts are tiny tube-shaped protein structures that form inside the kidney’s filtering tubes. Their presence often signals a kidney disorder, and the type of cast helps narrow down the diagnosis. Crystals can also appear, and their shape and composition hint at different conditions. Uric acid crystals are linked to gout, while other crystal types may suggest kidney stone risk or rare inherited metabolic disorders. The presence of crystals doesn’t always mean you’ll develop kidney stones, but it does indicate your urine chemistry favors stone formation.
How to Collect the Sample
Most urinalysis tests require a “clean-catch” midstream sample, which reduces contamination from skin bacteria. The process is straightforward but matters for accurate results. Wash your hands first, then use the provided antiseptic towelettes to clean the area around your urinary opening. For women, this means wiping front to back while holding the skin folds apart, using a fresh wipe each time (typically three wipes total). For men, clean the tip of the penis, retracting the foreskin if needed.
Start urinating into the toilet for a few seconds to flush out any bacteria near the opening. Then place the collection cup into the stream and fill it about halfway. Screw the lid on tightly and return it to the lab’s designated area. Skipping the cleaning step or catching the first part of the stream are the most common reasons for misleading results, particularly false signs of infection.
What Can Affect Your Results
Several everyday factors can throw off a urinalysis. Dehydration concentrates your urine and can make certain markers appear elevated when they otherwise wouldn’t be. Heavy exercise before the test can temporarily cause protein or blood to show up. Menstruation can contaminate a sample with blood that has nothing to do with urinary tract problems, which is why collection instructions recommend inserting a fresh tampon before providing the sample.
Certain medications and supplements also interfere with results. Vitamin C in high doses can cause false readings on several dipstick pads. Common over-the-counter drugs like ibuprofen, naproxen, diphenhydramine (Benadryl), dextromethorphan (found in many cough syrups), and ranitidine have all been associated with false-positive results on urine drug screens. Prescription medications including certain antidepressants, antipsychotics, and antibiotics can do the same. If you’re taking any medications regularly, let your provider know before the test so results can be interpreted correctly.
What Happens After Abnormal Results
An abnormal urinalysis is rarely a final diagnosis on its own. It’s a screening tool that flags areas needing closer investigation. If infection markers appear, a urine culture is typically the next step to identify the specific bacteria involved and determine which treatments will work. Protein or blood in the urine may lead to repeat testing over several weeks, since temporary causes like exercise or dehydration can produce a one-time abnormal result that doesn’t indicate any real problem.
Persistent protein in urine usually triggers blood tests to assess kidney function more directly. Glucose or ketones may prompt blood sugar testing if diabetes hasn’t already been diagnosed. Red blood cells that keep appearing could lead to imaging of the kidneys and bladder. The urinalysis itself is fast, with results often available within hours, but the follow-up tests it generates depend entirely on what the initial screen reveals.