Urinalysis can give providers a lot of information about a patient’s health. While most people associate urinalysis with urinary tract infections, there are many more common conditions that can be identified by analyzing a person’s urine, including proteinuria and hematuria. A urine sample can help providers identify infections, kidney problems, muscle damage, drug use, diabetes, and much more.
Related: Proteinuria and Hematuria
Proteinuria
Proteins naturally circulate in the bloodstream. Proteins are responsible for the transport of lipids and vitamins, immunity, and maintaining correct blood volume within the vasculature. They are large particles that typically cannot get through the filters of the kidneys and into the urine.
Proteinuria is defined as a urine protein creatinine ratio (UPCR) of more than 50 mg/mmol or a urine albumin creatinine ratio (UACR) of more than 30 mg/mmol.
It is uncommon for healthy patients to have routine urine screenings, and patients with proteinuria are often asymptomatic until their disease progresses. Any patients exhibiting signs of renal disease or problems with urination should be asked to provide a urine sample.
Patients in the early stages of renal disease may complain of urinary frequency, fluid retention, changes in the color of their urine, excessive thirst, or itchy skin.
Transient vs. chronic proteinuria
Transient proteinuria, where proteinuria is only present on a single occurrence can occur in healthy patients who are experiencing the following:
- Stress
- Fever
- Intense exercise
- Pregnancy
- Acute illness
Generally, transient proteinuria resolves when the condition resolves.
Chronic proteinuria is a long-term condition that does not resolve after an acute illness or stressful period. While it can be a benign finding, chronic proteinuria is often associated with problems in the kidneys. Higher levels of protein in the urine typically correlate with a more severe progression of chronic kidney disease.
Causes of renal disease that can lead to proteinuria include:
- Glomerulonephritis
- Tubular necrosis
- Diabetes mellitus, types I and II
- Connective tissue diseases
- Vasculitis
- Amyloidosis
- Myelomas
- Congestive heart failure
- Hypertension
Patients presenting with proteinuria should be evaluated for primary and secondary causes of renal disease.
Patient management of proteinuria
The diagnosis and management of patients with proteinuria depend on the underlying condition. While proteinuria is an abnormal finding, it is the symptom of an underlying problem that should be corrected, not a problem by itself.
The most common treatments for patients with proteinuria include antihypertensive medications and lifestyle changes.
Hematuria
Hematuria, or blood in the urine, is another abnormal finding that may indicate renal disease. It may be gross, meaning visible to the human eye, or microscopic, meaning only laboratory equipment can identify it.
When assessing a patient for hematuria, it is important to identify whether or not they are currently menstruating. Menstrual blood can contaminate a sample, leading a healthcare provider to incorrectly diagnose a patient with hematuria. Teaching a patient how to correctly perform a clean-catch for urine can help avoid this problem.
Gross hematuria is fairly easy to identify. Patients may report pink, red, or brown urine. In severe cases, they may even report seeing blood clots in their urine.
Microscopic hematuria is usually only identified when a provider asks for a urine sample to diagnose a condition. Patients with microscopic hematuria may report symptoms similar to a urinary tract infection, painful urination, kidney pain, or prostate problems.
Acute and chronic hematuria
Like proteinuria, hematuria can be acute or chronic. Injury or trauma to the urethra or a urinary tract infection are likely to cause acute hematuria. Chronic hematuria may indicate a more serious problem.
Chronic hematuria may indicate:
- Chronic kidney disease
- Sickle cell disease
- Bladder cancer
- Kidney cancer
- Ureteral cancer
- Urethral cancer
- Prostate cancer
- Polycystic kidney disease
- Renal calculi (kidney stones)
- Endometriosis
- Bladder inflammation
- Kidney inflammation
The most concerning cause of hematuria is cancer. Fortunately, this is rare. The American Family Physician Journal reports that only 5% of patients with chronic microscopic hematuria have a urinary tract malignancy.
The most common cause of hematuria is urinary tract infections. Antibiotics treat urinary tract infections, and usually resolve quickly. However, in older adults and other vulnerable populations, urinary tract infections can be serious. Providers should treat UTIs promptly and aggressively.
Understanding urinalysis for proteinuria and hematuria
Urinalysis is one of the most common medical procedures performed in hospitals and clinics. It is relatively inexpensive and noninvasive when compared to other types of laboratory testing. Providers can diagnose everything from pregnancy to chronic kidney disease using urinalysis.
It is important to remember that a urinalysis is usually just the first step in identifying a patient’s problem. Findings of proteinuria and hematuria can be benign or indicate serious disease. Nurses and other healthcare providers must be cautious and use their critical thinking skills to put together an entire clinical picture before assuming that they know what is going on with a patient.
Correctly collecting a urine sample
Whether via clean-catch collection or using a sterile catheter, nurses must be vigilant and use the correct technique when collecting a urine sample.
For patients who are able to collect their own urine, the nurse should be very clear in his or her instructions, asking the patient to perform a teach-back of how they will collect the sample. Using the correct tools and techniques ensures that the patient receives accurate results, allows the provider to identify the condition, and helps the patient get the treatment they need.
