What Causes a Lack of Protein in the Blood?

January 8, 2026 •

4 min read

According to a study cited by the Cleveland Clinic, hypoalbuminemia, a common form of hypoproteinemia, affects over 70% of hospitalized individuals over 70 years old. A lack of protein in the blood, known clinically as hypoproteinemia, can be caused by problems with protein synthesis, absorption, or excessive loss, indicating an underlying health issue.

Quick Summary

Low blood protein can result from issues related to production, absorption, or loss, often signaling underlying health problems like liver or kidney disease. Prompt diagnosis and treatment are essential for managing hypoproteinemia and preventing complications.

Key Points

Hypoproteinemia is an Indicator: A lack of protein in the blood (hypoproteinemia) is not a diagnosis itself but a sign of another underlying medical issue, ranging from nutritional deficiencies to severe organ disease.
Liver is the Main Producer: The liver is the primary organ responsible for synthesizing blood proteins like albumin; therefore, liver diseases such as cirrhosis are a common cause of low blood protein.
Kidneys Can Cause Protein Loss: Damaged kidneys, particularly in conditions like nephrotic syndrome, can leak essential proteins into the urine, leading to a significant drop in blood protein levels.
Malnutrition Impairs Raw Materials: Inadequate dietary protein intake, either from poor diet or malabsorption disorders like Celiac or Crohn's disease, deprives the body of the necessary raw materials for producing blood proteins.
Inflammation Increases Protein Breakdown: Systemic inflammation, often seen with critical illness, severe burns, or infections, increases the body's breakdown of proteins and can cause vascular leakage, leading to low blood protein levels.
Edema is a Common Symptom: Low albumin levels disrupt fluid balance, causing fluid to leak from blood vessels into tissues. This results in swelling (edema), particularly in the feet, ankles, and abdomen.
Timely Diagnosis is Crucial: Because hypoproteinemia can signal a serious condition, it is vital to consult a healthcare professional if symptoms appear. A doctor can use blood tests and other assessments to identify the root cause and recommend appropriate treatment.

A decrease in total protein levels in the bloodstream, a condition known as hypoproteinemia, is not a disease in itself but rather an indicator of an underlying health problem. The reasons for this deficiency are varied and can be categorized into three main issues: insufficient intake or absorption, decreased production by the body, or excessive loss of protein. Understanding the specific cause is crucial for effective treatment and management.

The Role of Protein in the Body

Proteins are fundamental building blocks for virtually every part of the human body. Beyond providing structural support, they are crucial for a host of physiological functions. In the bloodstream, proteins like albumin and globulin play several vital roles:

Maintaining Fluid Balance: Albumin, in particular, exerts osmotic pressure, which helps keep fluid within the blood vessels. When albumin levels drop, fluid can leak into surrounding tissues, causing swelling or edema.
Transporting Nutrients and Hormones: Proteins act as carriers, transporting essential vitamins, hormones, and minerals throughout the body.
Immune System Support: Globulin proteins are essential for producing antibodies that help fight off infections.
Blood Clotting: Certain globulins are necessary for proper blood coagulation to prevent excessive bleeding.

Causes Related to Insufficient Intake or Absorption

One of the most direct pathways to a lack of protein in the blood is a nutritional deficiency. However, it is important to distinguish between simple low intake and more complex issues of malabsorption.

Malnutrition and Restrictive Diets: Simply not eating enough protein-rich foods, whether due to poverty, disordered eating (like anorexia), or following a highly restrictive diet, is a primary cause. This is especially prevalent in developing countries but also affects elderly populations and those with certain chronic diseases.
Malabsorption Syndromes: Conditions that interfere with the small intestine's ability to absorb nutrients, including proteins, can lead to hypoproteinemia. Examples include:
- Celiac Disease: An autoimmune reaction to gluten that damages the lining of the small intestine.
- Inflammatory Bowel Disease (IBD): Chronic inflammation of the digestive tract, such as Crohn's disease, can impair nutrient absorption.
Gastrointestinal Disorders: In addition to malabsorption, some GI conditions cause protein-losing enteropathy, where proteins are lost through a damaged intestinal tract.

Causes Related to Decreased Production

The liver is the main site for synthesizing many of the body's proteins, especially albumin. Any significant damage to this organ can severely impede protein production.

Liver Disease and Cirrhosis: Chronic liver diseases, like hepatitis or cirrhosis, lead to the destruction of liver cells and a subsequent decline in the synthesis of plasma proteins. This is one of the most common causes of low blood protein levels.
Genetic Disorders: While rare, certain inherited conditions can cause a congenital defect in protein production. For example, congenital analbuminemia results in a near-complete absence of albumin in the blood.

Causes Related to Excessive Protein Loss

Even with adequate protein intake and production, the body can lose protein excessively through other systems.

Kidney Disease: The kidneys' filters (glomeruli) are normally designed to keep blood proteins in the bloodstream. In conditions like nephrotic syndrome, these filters become damaged and allow significant amounts of protein, particularly albumin, to leak into the urine. This is known as proteinuria and directly lowers blood protein levels.
Severe Burns: Extensive burns cause significant damage to the skin's protective barrier, leading to a substantial leakage of proteins from the blood through the wound sites.
Acute and Chronic Inflammation: Conditions involving widespread inflammation, such as sepsis, autoimmune diseases, or cancer, can lead to hypoproteinemia. Inflammation increases the breakdown (catabolism) of proteins and can cause them to leak out of the vascular system.

Comparison of Major Causes of Hypoproteinemia


Feature	Malnutrition/Malabsorption	Liver Disease	Kidney Disease	Inflammation/Critical Illness
Mechanism	Inadequate intake or poor absorption of protein.	Impaired synthesis of proteins (especially albumin) by the damaged liver.	Excessive loss of protein through damaged kidney filters into the urine.	Increased protein breakdown and vascular leakage due to systemic inflammation.
Primary Proteins Affected	Albumin and other plasma proteins.	Primarily albumin and globulins produced by the liver.	Primarily albumin, leading to proteinuria.	Albumin and other proteins involved in the inflammatory response.
Key Symptoms	Fatigue, weakness, muscle wasting, growth issues in children.	Jaundice, ascites (fluid in abdomen), edema, gastrointestinal bleeding.	Foamy urine, edema (especially feet, ankles, face), hypertension.	Severe edema, weakness, anemia, poor wound healing, increased metabolic rate.
Diagnostic Indicator	Diet history, serum albumin.	Liver function tests, imaging.	Urine albumin-to-creatinine ratio (UACR), serum protein.	Elevated inflammatory markers (e.g., C-reactive protein), serum albumin.

Conclusion

A lack of protein in the blood, or hypoproteinemia, is a serious sign that can point to a range of underlying health problems, from nutritional deficits to severe organ dysfunction. The causes are diverse and relate to issues of intake, synthesis, and excessive loss. Liver and kidney diseases are among the most common culprits, alongside malnutrition and significant inflammatory states. Anyone experiencing symptoms such as unexplained swelling, fatigue, or frequent infections should consult a healthcare professional for a proper diagnosis. Timely identification and treatment of the root cause are essential for preventing further complications and improving long-term health outcomes.

Medical News Today provides additional information on hypoproteinemia, including its symptoms, diagnostic tests, and treatment options, emphasizing that treatment is dependent on the specific underlying cause.

Frequently Asked Questions

Early signs of low protein, or hypoproteinemia, can include unexplained fatigue, weakness, or swelling (edema) in the ankles, feet, and hands. Fluid retention and puffiness, especially around the eyes in the morning, are common symptoms.

No, dehydration does not cause a true lack of protein. In fact, dehydration can artificially increase blood protein concentrations because there is less fluid volume. A true lack of protein is caused by issues with production, absorption, or loss, rather than fluid status.

Doctors test for low blood protein with a blood test that measures total protein levels, as well as specific proteins like albumin. A urine test may also be conducted to check for proteinuria, which indicates protein is being lost through the kidneys.

Not necessarily. While it can be a sign of a serious condition like liver or kidney disease, it can also be caused by less severe issues such as temporary malnutrition, a restrictive diet, or during pregnancy.

For hypoproteinemia caused by dietary deficiencies, increasing your intake of high-quality protein can help. This includes lean meats, eggs, fish, dairy products, nuts, legumes, and soy. Protein supplementation may also be recommended.

The liver is responsible for producing most blood proteins. When liver function is impaired due to damage from conditions like cirrhosis, it cannot produce enough protein, leading to low blood protein levels.

Healthy kidneys filter waste from the blood but retain essential proteins. In kidney diseases like nephrotic syndrome, the kidney's filtering units are damaged, allowing protein to leak into the urine and lowering blood protein levels.