Nutrition Diet: What is marasmus and kwashiorkor?

October 12, 2025 •

5 min read

According to the World Health Organization, severe acute malnutrition affects millions of children under five and is responsible for a significant number of child deaths each year. Severe malnutrition can present in different ways, with what is marasmus and kwashiorkor representing two distinct and life-threatening forms of protein-energy undernutrition.

Quick Summary

Marasmus and kwashiorkor are severe forms of malnutrition resulting from inadequate nutrient intake. Marasmus is a deficiency of all macronutrients, leading to severe wasting. Kwashiorkor is primarily a protein deficiency, characterized by fluid retention and swelling, particularly in the abdomen and limbs.

Key Points

Marasmus is starvation: Caused by a severe deficiency of all macronutrients, leading to a severely emaciated and wasted appearance.
Kwashiorkor is protein-specific malnutrition: Caused primarily by a protein deficiency, even if calorie intake is sufficient from carbohydrates, leading to characteristic edema and a distended belly.
Edema is the key differentiator: The presence of swelling due to fluid retention is the main sign distinguishing kwashiorkor from the wasting seen in marasmus.
Treatment requires careful management: Medical treatment follows a two-phase protocol (stabilization and rehabilitation) to prevent dangerous complications like refeeding syndrome.
Prevention is multi-faceted: Strategies involve improved access to nutritious food, promoting breastfeeding, enhancing sanitation, and addressing the underlying poverty that contributes to these conditions.
Long-term consequences can be irreversible: Both conditions can lead to permanent cognitive and physical disabilities, underscoring the importance of early intervention.

Understanding Severe Acute Malnutrition

Severe acute malnutrition (SAM) is a complex and life-threatening condition affecting millions globally, particularly children in low-income countries. It arises from an insufficient intake of energy, protein, fats, and micronutrients. The two most recognized and distinct forms of SAM are marasmus and kwashiorkor, which represent different physiological adaptations to severe nutritional deprivation. Understanding the specific causes, symptoms, and treatment for each is crucial for effective intervention and improved outcomes.

What is Marasmus?

Marasmus is a form of severe protein-energy malnutrition (PEM) resulting from a gross deficiency of all macronutrients, including carbohydrates, proteins, and fats. This is essentially starvation, where the body's energy requirements are unmet, forcing it to consume its own tissues to survive. The name comes from the Greek word marasmos, meaning "withering".

Causes and Risk Factors for Marasmus

Food Scarcity: Poverty, famine, and limited access to food are the most significant drivers.
Inadequate Weaning: Infants weaned off breast milk too early and not provided with a nutrient-rich alternative are highly vulnerable.
Infections: Frequent or chronic infections, especially diarrheal diseases, increase metabolic needs and decrease nutrient absorption, worsening the condition.
Chronic Illness: Conditions like chronic diarrhea, cystic fibrosis, or congenital heart disease can predispose a person to marasmus.

Key Symptoms of Marasmus

Severe Wasting: Marked loss of subcutaneous fat and muscle, leading to a severely emaciated, "skin and bones" appearance.
Loose Skin: The loss of fat causes the skin to hang in loose folds, particularly around the buttocks and thighs.
Wrinkled Appearance: The face may appear old and wrinkled due to the loss of buccal fat pads, sometimes called "monkey facies".
Poor Growth: Children exhibit stunted growth, both in height and weight.
Behavioral Changes: While often weak and lethargic, children with marasmus may appear relatively alert compared to those with kwashiorkor.
Poor Appetite: A diminished or complete loss of appetite is a common symptom.

What is Kwashiorkor?

Kwashiorkor, another severe form of PEM, is primarily a result of a severe protein deficiency, often occurring in individuals consuming enough total calories, but mostly from carbohydrates. This nutrient imbalance disrupts critical body functions, leading to different clinical signs than marasmus. The name originates from the Ga language of Ghana, meaning "the sickness the baby gets when the new baby comes," referring to a toddler being weaned for a new baby.

Causes and Risk Factors for Kwashiorkor

Protein-Poor Diet: The condition often develops after abrupt weaning from breast milk onto a diet high in carbohydrates but lacking protein, common in resource-poor areas.
Food Availability: In areas where staple foods like maize or rice are cheap and abundant, but protein-rich foods are scarce, the risk is higher.
Infections: Infections exacerbate the condition by increasing protein needs and causing nutrient loss through diarrhea or vomiting.
Gut Microbiome: Research suggests a link between alterations in the gut microbiota and the development of kwashiorkor.

Key Symptoms of Kwashiorkor

Edema: Bilateral pitting edema, or swelling, is the hallmark symptom, especially in the hands, feet, and abdomen. This can mask underlying wasting.
Distended Abdomen: A swollen, distended belly is characteristic due to fluid retention.
Fatty Liver: Impaired protein synthesis, particularly of lipoproteins, leads to fat accumulation in the liver, causing it to enlarge.
Skin and Hair Changes: The skin may show desquamation, resembling peeling paint. Hair becomes brittle, sparse, and may lose its color (the "flag sign").
Behavioral Changes: Children are often irritable, lethargic, and apathetic, with a poor appetite.
Reduced Muscle Mass: While masked by edema, muscle wasting is still present.

Marasmus vs. Kwashiorkor: A Comparison Table


Distinguishing Factor	Kwashiorkor	Marasmus
Primary Deficiency	Severe protein deficiency, often with adequate calorie intake.	Overall deficiency of both protein and calories.
Appearance	Edematous (swollen), sometimes called a "sugar baby" due to fluid retention.	Emaciated, shriveled, and wasted, with a "skin and bones" look.
Edema (Swelling)	Present and is a key clinical feature.	Absent.
Subcutaneous Fat	Often preserved or present to some degree.	Severely depleted, resulting in loose skin folds.
Appetite	Poor appetite and apathy are common.	Poor appetite is common, but children may appear relatively alert.
Age of Onset	Typically affects children between 6 months and 3 years old, especially post-weaning.	More common in infants under 1 year of age.
Weight Loss	Moderate weight loss, often masked by edema.	Severe weight loss.
Hair Changes	Becomes brittle, loses color, and is easily pulled out.	Thinning and dryness, less dramatic discoloration.
Skin Changes	Flaky paint dermatosis, hyperpigmentation.	Dry, thin, and wrinkled.
Fatty Liver	Liver enlargement due to fatty infiltration is common.	No fatty liver.

Diagnosis and Treatment of Severe Malnutrition

Diagnosis

Diagnosis of marasmus and kwashiorkor relies on a combination of physical examination, anthropometric measurements, and laboratory tests.

Physical Examination: Healthcare providers look for hallmark signs like edema (for kwashiorkor) or severe wasting and visible muscle loss (for marasmus).
Anthropometric Measurements: Body measurements such as weight-for-height and mid-upper arm circumference (MUAC) help quantify the severity of wasting.
Laboratory Tests: Blood tests can reveal low protein and albumin levels, anemia, and micronutrient deficiencies, which help confirm the diagnosis and guide treatment.

Treatment

Treating severe malnutrition is a delicate, multi-stage process, typically managed in a hospital setting, to prevent fatal complications like refeeding syndrome.

Stabilization Phase: The first 24-48 hours focus on correcting life-threatening issues. This includes treating or preventing hypoglycemia (low blood sugar), hypothermia (low body temperature), dehydration (using special rehydration solutions like ReSoMal), and electrolyte imbalances. Broad-spectrum antibiotics are given to combat assumed infections, as immune function is severely compromised. Cautious feeding begins with specialized, low-lactose milk formulas (F-75).
Rehabilitation Phase: Once the patient is stabilized, feeding is increased to promote rapid catch-up growth. Therapeutic milks (F-100) or ready-to-use therapeutic foods (RUTF) are used to provide high energy and protein. Micronutrient supplementation (excluding iron initially) is crucial.
Follow-up: Long-term success depends on continued nutritional support, education for caregivers on proper feeding and hygiene, and regular monitoring. Community-based care using RUTF has proven effective for uncomplicated cases.

Long-Term Impact and Prevention

The long-term consequences of severe malnutrition can be profound, especially if not treated early. These include irreversible cognitive and developmental delays, stunted growth, increased susceptibility to chronic diseases later in life, and reduced physical capacity. Effective prevention strategies are therefore critical:

Promote Breastfeeding: Exclusive breastfeeding for the first six months, followed by continued breastfeeding alongside nutritious complementary foods.
Improve Diet and Nutrition: Providing a diverse, protein-rich diet and educating families on proper nutrition and safe food preparation.
Enhance Public Health: Improving sanitation, access to clean water, and vaccination programs can reduce the incidence of infectious diseases that worsen malnutrition.
Combat Poverty: Addressing the root causes of food insecurity through economic development, social safety nets, and agricultural support is paramount.

Conclusion

Marasmus and kwashiorkor are distinct but equally severe manifestations of protein-energy malnutrition, demanding urgent medical attention. Marasmus, or starvation, is defined by total calorie deficiency and extreme wasting, while kwashiorkor is defined by protein deficiency, causing edema. Despite their differences, both are driven by food insecurity and poverty and require a structured, multi-phase treatment approach to avoid dangerous complications. The fight against these conditions requires a comprehensive approach, combining targeted medical treatment with long-term preventative measures to ensure children receive the nutrition necessary for a healthy life. For more detailed clinical guidelines, the World Health Organization provides comprehensive protocols for the management of severe malnutrition.

Frequently Asked Questions

The primary cause of marasmus is a severe deficiency of all macronutrients—proteins, carbohydrates, and fats—resulting from an overall lack of calories. This typically stems from food scarcity and extreme poverty.

Key symptoms of kwashiorkor include bilateral pitting edema (swelling), especially in the abdomen and limbs, skin lesions, hair changes (sparse, discolored), and apathy. The swelling can often mask underlying muscle wasting.

Yes, it is possible to have a mixed condition called marasmic-kwashiorkor, which presents with symptoms of both severe wasting and edema. This represents a continuum of severe acute malnutrition.

Diagnosis is based on a physical examination for clinical signs (wasting, edema), anthropometric measurements (mid-upper arm circumference, weight-for-height), and blood tests to check for protein levels and other deficiencies.

Refeeding syndrome is a potentially fatal shift in fluids and electrolytes that can occur when a severely malnourished person is fed too aggressively. The body’s altered metabolism during starvation makes it vulnerable to this life-threatening complication, which is why treatment must begin slowly under medical supervision.

The prognosis depends heavily on the timing and quality of treatment. While a full recovery is possible, untreated or severe cases can lead to permanent cognitive impairment, stunted growth, and long-term health issues.

Prevention focuses on ensuring a consistent, balanced, and nutritious diet, especially for young children. This includes promoting breastfeeding, providing nutrition education, improving sanitation and hygiene, and addressing poverty and food insecurity.