What Deficiency Causes Kwashiorkor and Marasmus? A Comprehensive Guide

December 19, 2025 •

4 min read

Worldwide, approximately 45 million children under five suffer from wasting, a key sign of severe malnutrition. Understanding what deficiency causes kwashiorkor and marasmus is crucial for diagnosing these life-threatening forms of protein-energy undernutrition.

Quick Summary

Kwashiorkor results from severe protein deficiency, causing edema and a distended belly. Marasmus, from an overall deficit of calories and protein, leads to severe muscle and fat wasting without edema.

Key Points

Kwashiorkor is a protein deficiency: It results primarily from a severe lack of protein, even if caloric intake is adequate.
Marasmus is an energy deficiency: It results from an overall lack of calories and all macronutrients—protein, carbohydrates, and fats.
Edema is a key sign of kwashiorkor: The severe protein deficit leads to fluid retention and swelling, especially in the abdomen and limbs.
Wasting is a key sign of marasmus: The body's consumption of its own tissues results in severe emaciation and visible loss of muscle and fat.
Both are linked to poverty: Both forms of malnutrition are most prevalent in regions with food scarcity, poor sanitation, and high rates of infectious disease.
Diagnosis is based on physical signs: The presence or absence of edema helps distinguish kwashiorkor from marasmus, in addition to weight-for-height measurements.

Understanding Severe Acute Malnutrition

Kwashiorkor and marasmus are two of the most severe forms of protein-energy malnutrition (PEM), a major global health concern. While both conditions arise from inadequate nutrient intake, the specific deficiencies driving them differ, leading to distinct clinical manifestations. Diagnosing and treating these conditions requires understanding these differences and addressing the underlying socioeconomic factors.

The Cause of Kwashiorkor: Primarily a Protein Deficiency

Kwashiorkor is predominantly a protein deficiency that occurs even when the overall caloric intake may seem sufficient, often from a high-carbohydrate diet. The name, from the Ga language of Ghana, means “the sickness the baby gets when the new baby comes”. It typically affects older infants and children who have been weaned from protein-rich breast milk and are then given a carbohydrate-heavy diet of grains or starches.

The most striking symptom of kwashiorkor is edema, or swelling, which occurs in the ankles, feet, and abdomen, masking the true extent of the child’s malnutrition. This swelling is caused by a lack of protein, specifically albumin. The body requires albumin to regulate fluid balance in the blood vessels. Without enough protein, albumin levels drop, causing fluid to leak from the bloodstream into surrounding tissues.

Contributing factors to kwashiorkor include:

Inadequate intake of essential amino acids and proteins.
Micronutrient deficiencies (e.g., zinc, antioxidants) that disrupt metabolic processes.
Exposure to environmental toxins, like aflatoxins, which can damage the liver.
Chronic infections that increase the body's nutrient needs and worsen malnutrition.

Other symptoms of kwashiorkor often include a fatty liver, skin lesions with a characteristic “flaky paint” appearance, brittle hair, and irritability.

The Cause of Marasmus: A Total Calorie and Protein Deficit

In contrast, marasmus is a severe energy deficiency resulting from an inadequate intake of all macronutrients: proteins, carbohydrates, and fats. This leads to a state of starvation, where the body's fat and muscle reserves are depleted to fuel basic metabolic functions. Marasmus often affects infants and very young children, but can occur at any age during prolonged undernutrition.

The primary clinical sign of marasmus is severe muscle and fat wasting. A child with marasmus appears visibly emaciated, with protruding ribs and an aged or "wizened" facial appearance due to the loss of subcutaneous fat. Unlike kwashiorkor, marasmus does not present with edema.

Factors contributing to marasmus include:

Widespread poverty and food scarcity in developing nations.
Inadequate breastfeeding or early weaning practices.
Infections that cause chronic diarrhea and prevent nutrient absorption.
Eating disorders like anorexia nervosa, though this is a less common cause in developed countries.

Symptoms of marasmus also include stunted growth, weakness, a suppressed immune system, and an increased susceptibility to infection.

Kwashiorkor vs. Marasmus: A Comparative Overview


Feature	Kwashiorkor	Marasmus
Primary Deficiency	Predominantly protein, with adequate or high carbohydrate intake.	Overall calorie and nutrient deficiency (protein, carbs, fat).
Edema (Swelling)	Present. Pitting edema in the abdomen, legs, and feet is a hallmark.	Absent. Wasting is severe and visible.
Body Appearance	Swollen abdomen and limbs, but emaciated elsewhere. Can mask true malnutrition.	Severely emaciated, “skin and bones.” Ribs and skeleton are prominent.
Subcutaneous Fat	Often retained, though muscle mass is lost.	Almost completely lost to provide energy.
Fatty Liver	Enlarged, fatty liver is a common symptom.	Not typically affected.
Age of Onset	Tends to occur after weaning, typically between 1 and 3 years.	More common in infants and very young children under 1 year.

Overlap and Complexities: Marasmic-Kwashiorkor

While kwashiorkor and marasmus are distinct syndromes, some children can present with symptoms of both conditions, a state referred to as marasmic-kwashiorkor. This mixed-feature malnutrition highlights the complexities of nutritional deficiencies, where the body experiences both severe energy and protein depletion, leading to a combination of wasting and edema. This condition is particularly dangerous and underscores the need for comprehensive nutritional assessment and management.

Conclusion: The Public Health Importance of Correct Diagnosis

Recognizing the different deficiencies is critical for effective treatment and public health strategy. Kwashiorkor, driven by a primary protein deficit, results in fluid imbalance and edema, while marasmus, caused by overall energy starvation, leads to profound wasting. Both are manifestations of severe malnutrition, often exacerbated by socioeconomic hardships, poor sanitation, and infectious diseases. Early and proper diagnosis is essential for treatment, which must be carefully managed to avoid complications like refeeding syndrome. Ultimately, addressing the root causes of poverty and food insecurity remains the most effective long-term strategy for preventing both kwashiorkor and marasmus. More information on malnutrition management is available from authoritative sources like the National Center for Biotechnology Information (NCBI): Recognition and Management of Marasmus and Kwashiorkor.

Frequently Asked Questions

Kwashiorkor is caused by a diet that is severely lacking in protein but often contains enough carbohydrates, while marasmus is caused by a diet that is deficient in all major macronutrients, including protein, carbohydrates, and fats.

The swelling, known as edema, is caused by the body's inability to produce enough albumin due to protein deficiency. Albumin is a protein that helps maintain fluid balance, and without it, fluid leaks from blood vessels into body tissues.

A child with marasmus appears severely emaciated or wasted, with loose, wrinkled skin and visible ribs and joints due to the loss of body fat and muscle.

Yes, a mixed form of malnutrition called marasmic-kwashiorkor can occur, where a person shows signs of both severe wasting and edema.

Treatment involves medical supervision, starting with slow refeeding and correcting fluid and electrolyte imbalances to prevent refeeding syndrome. The diet is gradually increased in calories and protein, supplemented with vitamins and minerals.

Kwashiorkor, with its associated edema and systemic issues like fatty liver and metabolic disturbances, is often considered more dangerous than marasmus and has a higher mortality rate if left untreated.

Infections, such as chronic diarrhea, can trigger or worsen both kwashiorkor and marasmus. A weakened immune system due to malnutrition makes individuals more susceptible to severe infections, creating a dangerous cycle.