Proteinuria: Causes, Types, Symptoms, and Treatment Plans

Proteinuria: Causes, Types, Symptoms, and Treatment Plans

Proteinuria is a medical condition characterized by the existence of an abnormally elevated quantity of protein in the urine. In a normal State, the kidneys remove extra waste products and water from the bloodstream but retain...

An overview 

Proteinuria is a medical condition characterized by the existence of an abnormally elevated quantity of protein in the urine. In a normal State, the kidneys remove extra waste products and water from the bloodstream but retain important substances like proteins. However, in cases of proteinuria, the kidneys allow large amounts of protein to escape into the urine, which can indicate a problem with kidney function.

There are different types of proteins that may be present in the urine, including albumin, globulins, and Bence Jones proteins. Albumin is the most measured protein in the urine, and its presence in the urine is often used as an indicator of kidney function. When proteinuria is present, the amount of albumin in the urine is usually elevated.

Know the frequency of proteinuria

Proteinuria is a reasonably frequent disorder, particularly in those with diabetes and high blood pressure.

Between 2013 and 2016, the prevalence of proteinuria among persons 20 years of age and older in the United States was estimated to be 7.7% by the National Health and Nutrition Examination Survey (NHANES).

There is limited data on the prevalence of proteinuria in India, but some studies have suggested that it is relatively common, especially among people with diabetes and hypertension.

One study conducted in a rural area of South India found that the prevalence of proteinuria among people with diabetes was approximately 20%, while another study conducted in a hospital setting in North India found that the prevalence of proteinuria among patients with hypertension was approximately 28%.

Other analyses have also implied that the prevalence of proteinuria may be higher among certain subpopulations in India, such as older adults or those with a history of chronic kidney disease.

Nevertheless, it's significant to cite that these investigations are limited in scope and may not accurately reflect the true prevalence of proteinuria in India as a whole.

Different types of proteinuria: understanding the complexities of kidney health.

Proteinuria can be classified into different types based on the underlying cause, the type of protein present in the urine, and the clinical presentation. Some of the most typical kinds of proteinuria include the following:

  • Glomerular proteinuria:

This type of proteinuria occurs when there is damage to the tiny blood vessels in the kidneys responsible for filtering waste and excess fluids from the blood. Glomerular proteinuria is often caused by conditions that affect the glomeruli, such as glomerulonephritis, lupus nephritis, or diabetic nephropathy. The proteins that are typically found in glomerular proteinuria are albumin, immunoglobulins, and complement proteins.

  • Tubular proteinuria:

Tubular proteinuria occurs when there is damage to the renal tubules, which are responsible for reabsorbing certain substances from the urine back into the blood. Tubular proteinuria can be caused by a variety of conditions, such as toxic drugs, infections, or multiple myeloma.

  • Overflow proteinuria:

Overflow proteinuria occurs when there is a surplus of a particular protein in the blood that the kidneys are unable to filter out completely. This type of proteinuria can be caused by conditions such as myeloma, amyloidosis, or Fabry disease. The proteins that are typically found in overflow proteinuria are specific to the underlying condition.

  • Functional proteinuria:

Functional proteinuria occurs in individuals who have normal kidney function, but the presence of protein in their urine is due to a benign cause, such as exercise or fever. This type of proteinuria does not require treatment.

  • Transient proteinuria:

Transient proteinuria is a temporary increase in protein in the urine that can be induced by a mixture of factors, such as dehydration, stress, or fever. Often, this kind of proteinuria goes away on its own.

Determining the type of proteinuria is important in diagnosing the underlying cause and determining the appropriate treatment plan. 

Don't ignore the signs of proteinuria - talk to your doctor.

This can occur due to a variety of underlying conditions that affect the kidneys or the urinary tract. Some of the most common causes of proteinuria include:

  • Infections:

This may happen because of several underlying renal or urinary tract diseases.

  • Medications:

Certain medications, such as NSAIDs, can cause kidney damage and increase the risk of proteinuria.

  • Kidney disease:

Proteinuria is frequently a symptom of kidney disease or injury, which can be brought on by illnesses including polycystic kidney disease, diabetic nephropathy, or glomerulonephritis.

  • Diabetes:

Proteinuria and other problems can result from high blood sugar levels harming the kidneys' blood vessels and filtration systems.

  • Increased blood pressure:

The kidneys' capacity to filter waste and extra fluid from circulation is hampered by the damaged blood vessels in the kidneys.

  • Genetics: In some cases, proteinuria may be inherited due to genetic mutations or conditions such as Alport syndrome.

Other conditions:

Other conditions that can cause proteinuria include heart failure, multiple myeloma, and amyloidosis.

It's important to note that not all cases of proteinuria require treatment, and the underlying cause of proteinuria may vary depending on individual circumstances. Hence, it's crucial to speak with a doctor if you encounter symptoms like altered urine color or odor, edema, or other indications of kidney disease.

Understanding the Origins of Proteinuria: A Journey into Pathogenesis.

The pathogenesis, or the process by which proteinuria develops, can vary counting on the underlying reason for the condition.

However, in general, proteinuria occurs when there is damage to the glomeruli, which are the small filters in the kidneys accountable for expelling waste products from the blood and producing urine. The glomeruli are lined with cells and have small pores called fenestrations that allow waste products to pass through but prevent larger molecules like proteins from escaping.

When there is damage to the glomeruli, either due to disease, inflammation, or other factors, these pores may become enlarged or develop gaps, allowing protein molecules to pass through and enter the urine. This can result in proteinuria, which is the presence of excess protein in the urine.

Protein in your urine? Don't ignore the sign - Know the signs and symptoms of proteinuria

In many cases, proteinuria may not cause any noticeable signs or symptoms, especially in its early stages. However, as the condition progresses or if the underlying cause of proteinuria worsens, some common signs and symptoms may include:

Foamy urine: Excess protein in the urine can cause it to appear foamy or frothy.

Swelling: Proteinuria can cause fluid retention in the body, leading to swelling in the feet, ankles, and other areas.

Fatigue: Proteinuria can cause fatigue and weakness, as the body may lose the protein that is needed for energy and muscle strength.

Urine changes: Changes in the color, odor, or frequency of urination may be a sign of proteinuria or other kidney-related issues.

High blood pressure: Proteinuria may be a sign of elevated blood pressure that can induce harm to the kidneys and other organs.

Nausea and vomiting: In severe cases, proteinuria can cause nausea and vomiting, which may be a sign of kidney damage or failure.

Difficulty breathing: Proteinuria can cause fluid buildup in the lungs, leading to difficulty breathing.

Loss of appetite: Proteinuria can lead to a loss of appetite and unintended weight loss.

Fatigue: Loss of protein can lead to fatigue and weakness, as the body may not have enough protein for energy and muscle strength.

Abdominal pain: In some cases, proteinuria can cause abdominal pain or discomfort.

Muscle cramps: Proteinuria can cause imbalances in electrolytes, which can lead to muscle cramps and weakness.

Proteinuria diagnosis: a crucial step towards kidney health.

The various diagnostic tests used for proteinuria:

Urine dipstick test:

A urine dipstick test is a quick test that can be conducted in a clinic or at home. It involves dipping a test strip into a urine sample, which changes color if the protein is present in the urine. While this test is convenient and inexpensive, it is not as accurate as other tests for proteinuria and can give false-positive or false-negative results.

Urine albumin-to-creatinine ratio (UACR) test:

The UACR test is a more accurate and sensitive test that measures the amount of albumin, a specific type of protein, in the urine compared to the amount of creatinine, a waste product. A urine sample is collected, and the UACR ratio is calculated. This test can detect small amounts of protein in the urine and is often used to monitor the progression of kidney disease. A UACR result of 30 mg/g or higher is considered abnormal.

  • Blood tests:

Blood tests can be used to estimate the levels of creatinine, blood urea nitrogen (BUN), and other characteristics of kidney function. Elevated levels of creatinine or BUN in the blood can indicate kidney damage or dysfunction. Blood tests can also help identify the underlying cause of proteinuria, such as diabetes, high blood pressure, or autoimmune diseases.

  • Radiography:

Radiography includes imaging tests such as X-rays, CT scans, or MRI scans. These tests can help detect any abnormalities or damage to the kidneys, urinary tract, or other related organs. They can also help diagnose the underlying cause of proteinuria, such as tumors or kidney stones, and assess the extent of the damage.

In addition to these tests, a healthcare professional may perform a thorough medical history and physical examination to help diagnose proteinuria and its underlying cause. They may ask about any symptoms, medications, or medical conditions and may perform a physical examination to check for signs of fluid retention, high blood pressure, or other related issues. Early detection and treatment of proteinuria and its underlying causes can help prevent further kidney damage and related complications.

A collaborative approach to help manages proteinuria and prevent kidney damage.

Treatment options for proteinuria include medications and surgeries, depending on the underlying cause of the condition. Here are some details on the different treatment options available:


  • Angiotensin-converting enzyme (ACE) inhibitors:

These medications work by loosening up blood vessels, which helps to lessen blood pressure and reduce the amount of protein that leaks into the urine. Enalapril, lisinopril, and ramipril are a few ACE inhibitors.

  • Angiotensin receptor blockers (ARBs):

Like ACE inhibitors, ARBs also help to relax blood vessels and decrease the quantity of protein that leaks into the urine.  ARBs comprise losartan, valsartan, and irbesartan.

  • Diuretics:

These medications help to increase urine output and reduce fluid buildup in the body, which can help to reduce the amount of protein in the urine. Examples of diuretics are hydrochlorothiazide and spironolactone.

  • Immunosuppressants:

Sometimes, proteinuria can be caused by an autoimmune disorder, in which case, immunosuppressant medications may be prescribed to help decrease inflammation and suppress immunity. Examples of immunosuppressants are cyclosporine, tacrolimus, and mycophenolate mofetil.


  • Kidney biopsy:

A kidney biopsy may be advised to help specify the underlying cause of proteinuria. In a kidney biopsy, a tiny specimen of kidney tissue is peeled off and analyzed under a microscope to look for signs of kidney disease or damage.

  • Nephrectomy:

In rare cases, proteinuria may be caused by a single kidney that is not functioning properly. In these cases, a nephrectomy (surgical removal of the affected kidney) may be recommended to help reduce proteinuria and improve kidney function.

Dietary Modifications:

 Here are some dietary changes that may be recommended:

  • Reduce salt intake:

Excess salt can cause fluid retention and increase blood pressure, both of which can exacerbate proteinuria. Therefore, it is recommended to limit salt intake to less than 2,300 milligrams per day.

  • Increase intake of fruits and vegetables:

Consuming a diet high in fruits and vegetables can help you acquire the essential nutrients and anti-inflammatory compounds you need to prevent kidney injury.

  • Restrict protein input:

Eating too much protein can put additional strain on the kidneys and increase proteinuria. Daily protein intake must be 0.8g.

  • Stay hydrated:

Drinking enough water can assist in flushing out excess protein and reduce the risk of dehydration, which can exacerbate kidney damage. It is suggested to drink at least 8-10 cups of water per day.

Avoid alcohol and caffeine:

Alcohol and caffeine may result in dehydration and increased blood pressure, which can worsen proteinuria. Therefore, it is advised to limit alcohol and caffeine intake.