What is proteinuria?
Proteinuria is an abnormal condition in which the kidney releases too much protein into the urine. Proteinuria is also known as albuminuria, due to the presence of one type of protein, albumin, in the urine. It is often caused by dysfunctional kidneys, high blood pressure, or diabetes. Proteinuria is a sign of chronic disease of or damage to the kidneys.
Proteins circulate within the blood, are essential for various body processes. Normally, the kidneys block the passage of protein, keeping it in the blood for delivery to the body’s tissues and organs. In proteinuria, however, protein in the blood passes through the kidneys and into the urine. Higher than normal blood pressure is a common cause of proteinuria. The kidneys are damaged by the elevated blood pressure, which eventually results in the passage of protein into the urine.
Other causes of proteinuria include diabetes, kidney infection, or other types of kidney inflammation. Left untreated, conditions that cause proteinuria can lead to a severe condition, end-stage renal (kidney) disease.
Some people with proteinuria do not have symptoms. However, if you have proteinuria, you may notice urine that appears frothy, or you may experience swelling in the body (edema). Proteinuria is usually detected during a simple urine analysis.
Proteinuria is a serious medical condition. Left untreated, proteinuria may lead to serious or life-threatening conditions. Seek immediate medical care (call 911) for serious symptoms including difficulty urinating (dysuria), inability to urinate, difficulty breathing (dyspnea) or shortness of breath, lethargy or altered mental status, or chest pain or pressure.
Seek prompt medical care if you are being treated for proteinuria but mild symptoms recur or are persistent.
What are the symptoms of proteinuria?
You may not experience symptoms of proteinuria; however, as the condition changes, a number of symptoms may result. The symptoms can vary in intensity among individuals.
Common symptoms of proteinuria
Any of these common symptoms of proteinuria can be severe:
- Change in urine output
- Frothy urine
- Recent weight change
- Swelling in abdomen
- Swelling in face
- Swelling in feet
- Swelling in hands
Serious symptoms that might indicate a life-threatening condition
In some cases, proteinuria can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms:
What causes proteinuria?
Proteinuria is the result of protein in the blood passing through the kidneys and into the urine. Diabetes and high blood pressure are common causes of proteinuria. Acute illness or dehydration can result in a transient increase in a urine protein measurement.
Renal causes of proteinuria
Proteinuria can be caused by a number of conditions or disorders of the kidney including:
Damage to the kidneys from certain drugs or toxins such as heavy metals
Glomerulonephritis (inflammation of the filtering structures of the kidneys)
Kidney infection (pyelonephritis) or inflammation
Other kidney diseases
Polycystic kidney disease (inherited disorder resulting in enlarged kidneys with multiple cysts)
Other causes of proteinuria
Proteinuria can also result from other conditions such as:
Amyloidosis (rare immune-related disorder characterized by protein buildup in organs and tissues that can cause serious complications)
Hypertension (high blood pressure)
Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
A number of factors increase the risk of developing proteinuria. Not all people with risk factors will develop proteinuria. Risk factors include:
African American, American Indian, Hispanic, or Pacific Islander ethnicity
Congestive heart failure
High blood pressure (hypertension)
Overweight or obesity
Reducing your risk of proteinuria
Some risk factors for proteinuria cannot be changed, such as age, genetics and ethnicity. However, risk factors related to lifestyle choices are modifiable, and they can reduce your risk of proteinuria. You can reduce your risk of developing proteinuria through the following actions.
You may be able to lower your risk of proteinuria by:
Maintaining a healthy blood pressure
Maintaining a healthy body weight
Maintaining healthy blood glucose levels if you have diabetes
Undergoing regular urine testing if you have risk factors for proteinuria
How is proteinuria treated?
Treatment for proteinuria begins with seeking medical care from your health care provider. To determine if you have proteinuria, your health care provider will ask you to provide a urine sample for laboratory testing.
Treatment for proteinuria depends on the underlying cause. However, the goal of treatment is to reduce the levels of protein in the urine. Several approaches are successful and include hypertensive therapy and, in the case of diabetic kidney disease, therapy to maintain normal blood glucose levels.
Treatments for proteinuria
Treatments that are used to control proteinuria or its underlying causes include:
Angiotensin-converting enzyme inhibitor (ACE) or angiotensin receptor blocker (ARB) medications to lower blood pressure and protect kidney function
Dietician consultation and a healthy meal plan
Insulin or other medications to help control blood sugar levels in people with diabetes
Treatment of any underlying chronic conditions
You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of proteinuria include: