Understanding What are the Laboratory Abnormalities of Kwashiorkor?

October 24, 2025 •

3 min read

Kwashiorkor is a severe form of protein-energy malnutrition, and studies show that over 90% of children with severe acute malnutrition, including kwashiorkor, have an electrolyte imbalance. Understanding what are the laboratory abnormalities of kwashiorkor is crucial for accurate diagnosis and effective management, particularly distinguishing it from other forms of malnutrition.

Quick Summary

Kwashiorkor causes significant laboratory changes, most notably severe hypoalbuminemia leading to edema. Other key abnormalities include critical electrolyte imbalances like low potassium, hypomagnesemia, and hyponatremia, along with anemia from nutrient deficiencies. Elevated liver enzymes due to fatty liver are also a common finding.

Key Points

Hypoalbuminemia is a hallmark: Critically low serum albumin is a defining laboratory feature of kwashiorkor, causing the characteristic edema.
Severe electrolyte imbalances are common: Patients frequently suffer from life-threatening low levels of potassium, magnesium, and sodium.
Anemia is nearly universal: The majority of kwashiorkor cases present with anemia, often stemming from deficiencies in iron and folate.
Elevated liver enzymes and fatty liver are typical: Impaired liver function due to fat accumulation is a key lab and clinical finding.
Multiple micronutrient deficiencies are detected: Kwashiorkor is associated with severe shortages of micronutrients like zinc and various vitamins.
Immune system dysfunction is reflected in labs: Lab results can show impaired immune function, such as reduced complement levels, increasing vulnerability to infections.

Core Lab Findings in Kwashiorkor

Laboratory evaluation is essential for confirming a diagnosis of kwashiorkor, a type of severe acute malnutrition (SAM) primarily caused by protein deficiency. While clinical signs like edema are characteristic, laboratory tests reveal the underlying metabolic disturbances affecting multiple organ systems. The most defining lab abnormality is severe hypoalbuminemia, a direct consequence of inadequate protein synthesis.

Protein and Liver Function Abnormalities

Hypoalbuminemia and Hypoproteinemia: The hallmark of kwashiorkor is a significantly low serum albumin concentration (hypoalbuminemia), often falling to 10–25 g/L. This occurs because the liver, lacking adequate protein building blocks, cannot produce sufficient albumin. This low level of plasma protein reduces oncotic pressure, causing fluid to leak from blood vessels into surrounding tissues, which manifests as the characteristic edema. Total serum protein levels are also reduced (hypoproteinemia).

Liver Enzyme Elevation: Kwashiorkor frequently causes a fatty liver (hepatic steatosis) due to impaired lipid transport from the liver. As a result, liver enzymes like aspartate transaminase (AST), alanine transaminase (ALT), and gamma-glutamyl transpeptidase (GGT) are often elevated, indicating liver stress and dysfunction. A liver biopsy would typically reveal diffuse fatty changes.

Electrolyte and Metabolic Imbalances

Severe Electrolyte Deficiencies: The search results consistently highlight severe electrolyte disturbances in kwashiorkor. Key abnormalities include:

Hypokalemia: Critically low serum potassium levels are common due to inadequate dietary intake, vomiting, and diarrhea. This can lead to muscle weakness, cardiac arrhythmias, and paralytic ileus.
Hypomagnesemia: Magnesium is often depleted, which can exacerbate hypokalemia and hypocalcemia, and potentially trigger seizures.
Hyponatremia: Low serum sodium levels are frequently found, though total body sodium may be paradoxically increased due to the edema.
Hypocalcemia: Low serum calcium is also a common finding.

Other Metabolic Changes: Malnutrition severely impacts the body's metabolic processes. Patients with kwashiorkor may present with:

Hypoglycemia: Especially during initial treatment, low blood sugar is a risk.
Low Blood Urea Nitrogen (BUN): Due to very low protein intake and reduced muscle mass, BUN levels are often low.
Metabolic Acidosis: This can occur, particularly with complications like infection.

Hematological and Immune System Abnormalities

Anemia: Anemia is a near-universal finding in kwashiorkor patients, seen in over 97% of children in one study. The type of anemia can vary, but iron and folate deficiencies are major contributors.

Iron Deficiency Anemia: Characterized by microcytic, hypochromic red blood cells and low serum iron.
Megaloblastic Anemia: Deficiencies in folate and vitamin B12 can cause megaloblastic changes in the bone marrow, as reported in a significant portion of patients.

Immune Dysfunction: Severe malnutrition significantly compromises the immune system, leading to heightened susceptibility to infections. Lab findings reflecting this include:

Reduced Complement Levels: Lowered complement (C3, C4) may be observed, impairing the immune response.
T-cell Dysfunction: Protein and nutrient deficiencies depress cell-mediated immunity.

Micronutrient Deficiencies: Tests often reveal a host of micronutrient deficiencies, including:

Zinc deficiency: Often severe and can mimic other skin conditions.
Vitamin A and D deficiencies: Are frequently present and require supplementation.

Comparing Laboratory Findings: Kwashiorkor vs. Marasmus

While both kwashiorkor and marasmus are forms of severe acute malnutrition (SAM), their laboratory profiles show distinct differences, which help clinicians differentiate between the two conditions.


Lab Parameter	Kwashiorkor	Marasmus
Serum Albumin	Markedly low (hypoalbuminemia).	Often near-normal or only slightly low.
Edema	Present, caused by low plasma oncotic pressure.	Absent, as albumin levels are maintained via body protein breakdown.
Fatty Liver	Characteristic feature; liver enzymes (AST, ALT) often elevated.	Generally absent.
Electrolytes	Frequent and severe disturbances (hypokalemia, hypomagnesemia).	Disturbances occur, but often less severe than in kwashiorkor.
Micronutrients	Often more profound depletions of antioxidant minerals.	Significant deficiencies common, but profile may differ.
Amino Acids	Imbalances in amino acids and biogenic amines are more pronounced.	Differently affected metabolic profiles.

Conclusion: The Importance of Comprehensive Lab Work

The constellation of laboratory abnormalities observed in kwashiorkor provides a detailed picture of the systemic effects of severe protein malnutrition. From the defining hypoalbuminemia that explains the physical edema to the critical electrolyte and metabolic derangements, these lab results are more than just indicators; they are essential for guiding effective treatment protocols. Correcting these imbalances with careful nutritional rehabilitation, including gradual protein and micronutrient repletion, is vital for recovery and survival. A comprehensive laboratory workup allows clinicians to monitor the patient’s progress, address underlying nutrient deficiencies, and prevent life-threatening complications like refeeding syndrome. For more information on nutritional deficiencies, the National Institutes of Health offers extensive resources on protein-energy malnutrition via their PMC database.

Frequently Asked Questions

The most important laboratory finding in kwashiorkor is severe hypoalbuminemia, which is a critically low level of serum albumin. This is the primary cause of the widespread edema (swelling) that distinguishes kwashiorkor from other types of severe malnutrition.

Electrolyte imbalances are common due to inadequate dietary intake, vomiting, and diarrhea. Key deficiencies include hypokalemia (low potassium), hypomagnesemia (low magnesium), and hyponatremia (low sodium), all of which can have serious consequences if not corrected.

Fatty liver (hepatic steatosis) is a consistent and characteristic feature of kwashiorkor. It occurs because the liver cannot synthesize and export enough lipoproteins, causing fat to accumulate within liver cells. This often leads to elevated liver enzyme levels, such as AST and ALT.

Anemia is extremely common in kwashiorkor. It can be due to iron deficiency, causing microcytic and hypochromic red blood cells, and also folate deficiency, which can lead to megaloblastic changes in the bone marrow. The anemia is often severe.

The key laboratory difference is that kwashiorkor involves marked hypoalbuminemia and edema, while marasmus typically presents with near-normal serum albumin and no edema. Kwashiorkor also consistently shows fatty liver changes and more pronounced electrolyte and micronutrient depletions than marasmus.

Yes, hypoglycemia (low blood sugar) is a significant metabolic abnormality that can occur, especially during the early stages of refeeding treatment. Care must be taken to prevent and manage this complication.

Severe protein malnutrition compromises the immune system. Laboratory tests can reveal suppressed cell-mediated immunity and reduced complement levels. This leaves patients highly susceptible to infections, which are a major cause of death.