Hypoalbuminemia is a blood albumin level of less than 3.5 grams per deciliter (g/dL). It often occurs as a result of a serious underlying medical condition, such as kidney, liver, or heart failure.
Albumin is the most abundant protein in the bloodstream. It plays several vital roles, including preventing fluid from leaking out of blood vessels and serving various anti-inflammatory functions.
Low albumin levels cause swelling due to fluid buildup in the tissues. Low levels are associated with generalized weakness, low muscle mass, and increased inflammation.
This article will discuss hypoalbuminemia, including its symptoms, causes, diagnosis, and management. It will also explore the possible complications of a low albumin level and what it may mean regarding medical outcomes.
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What Is Albumin and How Does It Relate to Hypoalbuminemia?
Albumin is a protein made exclusively by liver cells. It comprises half of the protein content in a healthy individual's bloodstream.
Albumin plays a diverse role in the body. It's responsible for the following functions:
- Keeping fluid from leaking out of capillaries into other tissues
- Binding to various substances, such as bilirubin, calcium, magnesium, vitamin D, thyroid hormone, zinc, and copper
- Exerting antioxidant activities by scavenging free radicals (highly reactive molecules produced by cell metabolism), like nitric oxide
- Helping block platelets (blood cells active in clotting) from clumping together to clot blood
When albumin levels are low—which is defined as less than 3.5 mg/dL—the above functions are negatively impacted, resulting in potentially serious symptoms and complications.
Causes of Hypoalbuminemia
Hypoalbuminemia is found frequently in people with acute or chronic medical conditions, especially those who are hospitalized.
The following health conditions or scenarios may cause hypoalbuminemia:
- Liver disease causes hypoalbuminemia because albumin is only made in the liver. In cirrhosis (when liver tissue is replaced with scar tissue), reduced albumin levels predict prognosis (disease outcome).
- End-stage renal (kidney) disease (ESRD) is the most advanced stage of chronic kidney disease. Albumin is lost through the urine (proteinuria) and dialysis. Hormonal changes and poor nutritional intake in ESRD also contribute to hypoalbuminemia.
- Nephrotic syndrome occurs when the kidneys' filtering units malfunction, allowing large amounts of albumin to be removed from the body through the urine.
- Chronic heart failure is associated with low albumin levels in approximately 25% of cases. Low albumin levels are thought to be due to inflammatory stress in the body and impaired albumin production from liver congestion.
- Sepsis is a severe, whole-body reaction to an infection in the bloodstream. It is associated with reduced liver production of albumin, increased leakage of albumin into tissues, and albumin breakdown.
- Severe burn injuries allow albumin loss through the burn wound. Early hypoalbuminemia in the first six hours after the injury is associated with an increased risk of death.
- Protein-losing enteropathy (PLE) describes rapid albumin leakage into the intestines. PLE is linked to more than 60 diseases, including digestive conditions like Crohn's disease and celiac disease.
- Kwashiorkor is a severe type of malnutrition that occurs in infants and children consuming a low-protein, normal-calorie diet.
- General inflammation in the body from chronic disease (e.g., alcohol use disorder and obesity), lifestyle (e.g., smoking), or the natural aging process may contribute to or cause hypoalbuminemia.
What Are the Symptoms of Low Albumin?
The primary symptom of hypoalbuminemia is swelling, called edema, which results from fluid leaking out of blood vessels into surrounding tissues.
Edema may occur in the feet, ankles, hands, around the eyes, lower back, abdomen, genitalia, or lungs. It can also be generalized—what's known as anasarca.
Other common symptoms of low albumin include unusual tiredness and generalized weakness.
Individuals with low blood albumin levels can also experience symptoms and signs related to the underlying cause.
For example, hypoalbuminemia from nephrotic syndrome causes profound fluid-related weight gain, foamy urine, trouble breathing with activity, and high blood pressure.
Likewise, with cirrhosis, besides fluid buildup in the abdomen (ascites), people may experience jaundice (yellowing of skin and eyes), discomfort in the upper right area of the abdomen, loss of appetite, and confusion.
Other notable symptoms include diarrhea in individuals with protein-losing enteropathy and a remarkably distended belly in kwashiorkor.
How Hypoalbuminemia Is Diagnosed
An albumin blood test and a comprehensive metabolic panel (CMP) can detect a low albumin level.
The advantage of a CMP is that it provides an overview of how well a person's kidneys and liver work in addition to measuring albumin levels.
What Does a CMP Measure?
A CMP measures albumin, total protein, bilirubin, liver enzymes, calcium, blood glucose (sugar), sodium, potassium, carbon dioxide, chloride, blood urea nitrogen (BUN), and creatinine.
When hypoalbuminemia is diagnosed, a healthcare provider can order additional tests to uncover the cause of or evaluate for complications related to low albumin levels.
Examples of such tests include:
- A/G ratio is a blood test that compares the amount of albumin to another group of proteins called globulins.
- C-reactive protein (CRP) is a blood test that looks for generalized inflammation in the body.
- Urinalysis is a urine-based test that checks for excess protein in the urine.
- Fecal studies are stool-based tests that check for the presence of a protein marker called alpha-1-antitrypsin.
Different types of ultrasounds (imaging tests that use sound waves to create pictures) may also be ordered, such as:
- An echocardiogram to evaluate the heart
- A kidney ultrasound to evaluate kidney size and blood flow
- An abdominal ultrasound to evaluate for liver disease and quantify ascites
Sonography: How a Sonogram Test Works and What It Shows
How to Treat and Manage Hypoalbuminemia
Managing hypoalbuminemia depends on the underlying cause.
Examples of medications for conditions associated with hypoalbuminemia include:
- A diuretic (water pill) to address fluid buildup in liver, kidney, or heart failure
- An angiotensin-converting enzyme (ACE) inhibitor to reduce proteinuria in kidney disease
- Antibiotics administered intravenously (through the vein) to kill bacteria in sepsis
- Anti-inflammatory drugs like steroids (e.g., prednisone) to calm down the immune system in certain causes of protein-losing enteropathy and nephrotic syndrome
In addition to medication, a vast array of therapeutic and supportive interventions can help manage the underlying cause of hypoalbuminemia.
For example, for people with cirrhosis-related ascites, a hepatologist (a doctor specializing in liver disease) can perform paracentesis. During this procedure, large volumes of fluid are removed from the belly.
Avoiding alcohol to prevent worsening liver disease and further albumin reduction is also paramount to the care of someone living with cirrhosis.
Are Albumin Infusions Helpful?
Albumin infusions for hypoalbuminemia in critical illness are controversial. Though infusions are beneficial for complications related to cirrhosis and, perhaps, in select cases of sepsis, in other instances, they may offer no benefit or even pose harm.
What Foods Are High in Albumin?
Dietary interventions, namely a high-protein diet, can help prevent or manage some causes of hypoalbuminemia (e.g., people with chronic kidney disease on dialysis or protein-losing enteropathy).
Animal sources rich in protein include:
- Meats like chicken, turkey, beef, and pork
- Fish, like salmon, mackerel, and tuna
- Dairy products like milk, cheese, yogurt, and eggs
Plant sources rich in protein include:
- Beans like kidney beans, pinto beans, white beans, black beans, lima beans, and edamame
- Peas like chickpeas and black-eyed peas
- Lentils
- Soy products like tofu
- Quinoa
- Nuts and seeds like almonds, walnuts, pumpkin, and peanut butter
In some cases, dietary supplements or a feeding tube may also be recommended, especially if nutritional needs cannot be met through food.
Meet With a Dietitian
Along with the guidance of a healthcare provider, a registered dietitian nutritionist (RDN) can help you devise a meal plan based on your daily protein intake goals and personal preferences.
High-Protein Foods for Every Eater
Possible Complications of Hypoalbuminemia
Hypoalbuminemia is associated with several poor medical outcomes.
For instance, one large study revealed that in people undergoing various surgeries for cancer, heart, or orthopedic conditions, hypoalbuminemia was associated with a higher risk of postoperative complications (e.g., infections) and death.
Another study that examined nearly 800 people with colorectal cancer found that hypoalbuminemia was associated with anemia (low red blood cell count), increased inflammation throughout the body, and low muscle mass.
Hypoalbuminemia has also been found to serve as a marker of disease severity—for example, in people infected with COVID-19 or community-acquired pneumonia (lung infection).
Other possible complications of hypoalbuminemia include:
- Diminished cognitive (memory, thinking, problem solving) and immune system function
- Lower quality of life and life expectancy
- Prolonged and recurrent hospitalizations
- Increased risk of frailty (a syndrome in older adults associated with increased falls, weight loss, weakness, and low physical activity).
What’s the Outlook for Someone with Hypoalbuminemia?
Albumin is a possible marker of adverse medical outcomes in severe illness. However, understand that several other factors play a role in assessing a person's prognosis.
Some of these factors include:
- The cause of the hypoalbuminemia
- How promptly and effectively the underlying cause is treated
- The nutritional status of the individual
- The overall health and lifestyle of the individual
As such, assessing the outlook of someone with hypoalbuminemia requires a deep dive into several facets of a person's overall health.
If you or a loved one has hypoalbuminemia, be sure to discuss the next steps with your healthcare provider.
Summary
Hypoalbuminemia refers to low blood albumin levels. It has many potential causes, including kidney or liver disease. Because albumin—the most abundant protein in the bloodstream—keeps fluid inside blood vessels, swelling from fluid accumulating within tissues occurs when levels are low.
Along with swelling, hypoalbuminemia is associated with low muscle mass, inflammation, and various adverse outcomes, like prolonged or recurrent hospitalizations and a more severe disease course.
An albumin blood test can help to diagnose hypoalbuminemia, and from there, additional blood, urine, stool, and imaging tests can unveil the cause. Treatment focuses on managing the underlying condition and may involve dietary interventions like consuming high-protein foods or abstaining from alcohol.
