Urinary Protein: Causes, Kidney Health, and Blood in Urine - Urology

Dr. Cai Zongyou reply Urology

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Hello: In response to your question.
The couple, Chun-Jiao and Zhi-Ming, walked into the urology clinic with worried expressions.
Recently, their company conducted health check-ups, and Chun-Jiao's report showed a positive reaction for hematuria, indicating the presence of red blood cells in her urine.
Concerned, she asked the doctor, "Could it be kidney stones? Or cancer? Is it serious?" Zhi-Ming, feeling a bit embarrassed, asked the doctor, "I've noticed bubbles in my urine lately, and sometimes my lower back feels a bit sore.
The check-up also revealed proteinuria.
Am I experiencing kidney deficiency? Will this affect my future happiness?" Hematuria and proteinuria are two major reasons patients seek consultation in nephrology.
As more people undergo regular health check-ups and become increasingly aware of their health, the number of patients seeking medical advice has also risen.
Today, we will discuss the examination, causes, and treatment of hematuria and proteinuria through these two cases.
First, let's talk about hematuria.
As the name suggests, hematuria means the presence of blood in the urine.
When you look at the report, there are two situations that can be classified as hematuria: one is a positive occult blood test, which is detected using test strips; the other is the presence of a certain number of red blood cells in the urine, which is determined through microscopic examination.
Both indicate a problem in the urinary system.
However, the occult blood test can sometimes be influenced by food or medications, so it is necessary to conduct both tests for a more accurate diagnosis.
Hematuria can be classified into gross hematuria, which is visible to the naked eye, and microscopic hematuria.
Gross hematuria does not necessarily mean that the urine will appear red, as some foods and medications can affect urine color, such as beets and anti-tuberculosis drugs.
It is important to distinguish this.
Additionally, female patients may experience blood in their urine during menstruation, so if hematuria is detected around the menstrual period, there is no need to panic; a recheck can be done five to six days after menstruation.
Microscopic hematuria refers to the presence of red blood cells that are not visible to the naked eye but can be detected under a microscope, showing more than three red blood cells per high-power field.
Whether it is gross hematuria or microscopic hematuria, both indicate that there may be lesions in any part of the urinary tract (kidneys, ureters, bladder, urethra), and further examination is required.
Additional examinations may include X-rays of the urinary system and renal ultrasound to rule out bleeding caused by kidney stones or tumors.
Furthermore, a more detailed examination of the red blood cells in the urine (such as a Wright's stain examination) is necessary to determine whether the red blood cells are intact, which helps differentiate between "glomerular hematuria" and "non-glomerular hematuria." Glomerular hematuria refers to kidney damage caused by infections or systemic diseases affecting the glomeruli, while non-glomerular hematuria indicates bleeding due to inflammation, stones, trauma, or tumors in any part of the urinary tract.
Next, let's discuss proteinuria.
The presence of bubbles in urine does not necessarily indicate proteinuria, especially since men tend to produce more bubbles when urinating while standing.
To confirm the presence of proteinuria, it is best to conduct a urine analysis for accuracy.
Normally, a person excretes 40 to 80 milligrams of urine protein daily, with a maximum of 150 milligrams.
Therefore, if urine protein exceeds 150 milligrams per day, it is considered abnormal.
When patients seek medical attention for proteinuria, urologists will typically request a 24-hour urine collection for testing.
Some proteinuria is not persistent; for example, "functional proteinuria" occurs temporarily during intense exercise, fever, high-temperature work, or labor, often seen in adolescents.
"Postural proteinuria," also known as positional proteinuria, occurs when the patient is lying down without proteinuria, but proteinuria develops upon standing and usually is less than one gram (1000 milligrams) per day.
Both types are considered benign proteinuria, with a good prognosis, requiring no medication, only regular follow-up.
Persistent proteinuria usually indicates that there is an issue with the kidney's structure (including the glomeruli and renal tubules), often associated with systemic diseases such as diabetes, hypertension, lupus erythematosus, or glomerulonephritis, as well as drug-induced interstitial nephritis.
If daily urine protein loss exceeds 3.5 grams, it is termed "nephrotic syndrome." Treatment to improve proteinuria can only be determined once the underlying cause is identified, to prevent complications such as malnutrition and edema.
Both hematuria and proteinuria are the first warning signs of problems in the kidneys or other urinary organs, and should not be taken lightly.
If you experience these symptoms, please seek help from a urologist promptly.
Do not rely on folk remedies, as delaying treatment can lead to lifelong regrets.

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Reply Date: 2007/02/11