What is marasmus?: Understanding the causes and impact of severe malnutrition

October 4, 2025 •

4 min read

According to the World Health Organization, approximately 45 million children under five suffer from wasting, with marasmus representing a severe form of this acute malnutrition. Understanding what is marasmus is crucial for recognizing and addressing this life-threatening condition, which results from a severe lack of calories and protein.

Quick Summary

Marasmus is a severe form of protein-energy malnutrition defined by extreme wasting of muscle and fat due to a prolonged lack of overall calories and nutrients. It predominantly affects young children in low-resource settings and requires a structured nutritional rehabilitation plan for recovery.

Key Points

Severe Wasting: Marasmus is the most common form of severe protein-energy malnutrition, characterized by extreme loss of muscle and body fat.
Visible Emaciation: Individuals with marasmus appear emaciated, with wrinkled skin and a prominent skeletal structure due to depleted fat stores.
Distinguished from Kwashiorkor: Unlike kwashiorkor, marasmus does not cause edema or swelling, though both are serious forms of undernutrition.
Multifactorial Causes: Poverty, food scarcity, infections, and inadequate feeding practices are all significant contributing factors to marasmus.
Phased Treatment: Treatment requires a careful, staged approach to avoid life-threatening refeeding syndrome, starting with stabilization and gradually introducing nutrients.
High-Risk Population: Marasmus primarily affects infants and young children under five in developing regions, but it can also impact the elderly or chronically ill.
Long-term Effects: Even with successful treatment, severe cases in childhood can lead to long-term health issues like developmental delays and stunted growth.

What is marasmus?: A deep dive into severe malnutrition

Marasmus is a severe and life-threatening form of protein-energy malnutrition (PEM) caused by a significant deficiency in overall calorie and nutrient intake. The term comes from the Greek word for 'wither,' describing the severe emaciation associated with the condition. This lack of nutrients forces the body to break down its own tissues for energy. It is most prevalent in young children and infants due to their high nutritional needs for growth, but it can affect individuals of any age. The body enters survival mode, breaking down fat stores and muscle tissue in a process known as wasting, a key characteristic of marasmus. This also leads to a reduced metabolic rate and a weakened immune system.

Recognizing the signs: Symptoms of marasmus

Identifying the symptoms of marasmus is critical for prompt treatment.

Visible wasting: Severe loss of subcutaneous fat and muscle leads to an emaciated appearance with protruding ribs and joints and loose, wrinkled skin.
Wizened appearance: In children, loss of facial fat can create an 'old man' or 'monkey-like' look.
Stunted growth: Growth is severely impaired, resulting in low weight and potentially reduced height for age.
Lethargy and apathy: Affected individuals often appear tired, withdrawn, or irritable.
Digestive issues: The digestive system can be impaired, leading to poor nutrient absorption and chronic diarrhea.
Weakened immunity: A suppressed immune system increases susceptibility to potentially fatal infections.
Other symptoms: Dry skin, brittle hair, sunken eyes, low blood pressure, and a slow heart rate may also be present.

Root causes of marasmus: A complex issue

Marasmus arises from a combination of factors, primarily linked to socioeconomic conditions and health problems.

Poverty and food insecurity: Limited access to sufficient and nutritious food is a major cause, especially in developing regions.
Chronic and recurrent infections: Illnesses like diarrhea, malaria, tuberculosis, or HIV/AIDS deplete the body's resources and hinder nutrient absorption.
Inadequate feeding practices: Improper breastfeeding or the use of diluted complementary foods can contribute to malnutrition in infants.
Medical conditions: Certain chronic illnesses or disorders affecting nutrient absorption can also be a cause.
Lack of education: Limited knowledge of proper nutrition and hygiene can worsen the problem.
Psychosocial factors: Neglect can also lead to severe undernutrition.

Marasmus vs. Kwashiorkor: A comparative perspective

Marasmus and kwashiorkor are the main types of protein-energy malnutrition, distinguished by their specific nutritional deficiencies.


Feature	Marasmus	Kwashiorkor
Primary Cause	Overall deficiency of calories, protein, and all macronutrients.	Primarily a severe protein deficiency, often with adequate or high carbohydrate intake.
Visible Symptom	Severe wasting of fat and muscle, leading to an emaciated appearance.	Edema (swelling) due to fluid retention, particularly in the abdomen, legs, and face.
Appearance	Wrinkled, loose skin hangs on a visibly emaciated frame; the individual appears 'withered'.	Swollen or distended belly and face; the individual can appear falsely plump.
Weight	Significantly below standard weight for age due to wasting.	Body weight can be deceptively close to normal due to fluid retention.
Appetite	Can be voraciously hungry in the initial stages, though anorexia is also common in severe cases.	Often poor or absent.
Age of Onset	More common in infants under one year old.	More common in children over 18 months, often after weaning.

The treatment approach: Phased nutritional rehabilitation

Treating marasmus is a delicate, multi-stage process requiring medical supervision to prevent refeeding syndrome, a dangerous complication.

Stage 1: Stabilization. Immediate priorities include treating life-threatening issues like dehydration and infections with rehydration and antibiotics. Feeding starts cautiously.
Stage 2: Nutritional Rehabilitation. Once stable, the focus shifts to replenishing nutrients with specialized therapeutic milk formulas. Calorie intake is gradually increased to promote catch-up growth.
Stage 3: Follow-up and Prevention. After recovery, ongoing support, nutritional education, weight monitoring, and addressing underlying factors are essential to prevent relapse.

Prevention strategies for marasmus

Preventing marasmus involves addressing both immediate nutritional needs and underlying causes.

Adequate nutrition: Ensuring a varied and sufficient diet is the best prevention.
Promoting breastfeeding: Exclusive breastfeeding for the first six months and nutrient-rich complementary foods are vital for infants.
Improving sanitation and hygiene: Clean water and sanitation reduce the risk of infections that contribute to malnutrition.
Nutritional education: Educating families on proper nutrition and food preparation is empowering.
Addressing poverty and food insecurity: Long-term solutions involve global efforts to alleviate poverty and improve food access.
Screening and early intervention: Regular monitoring of vulnerable populations can detect malnutrition early.

Conclusion: Addressing the global challenge of marasmus

Understanding what is marasmus reveals a complex health crisis rooted in more than just food scarcity. It is a severe form of malnutrition with lasting negative impacts on physical and cognitive development, especially in children. While treatment exists, prevention through adequate nutrition, public health initiatives, and socioeconomic support is crucial. By recognizing the risk factors and implementing comprehensive strategies, the global community can work to reduce marasmus and improve the health of vulnerable populations. For more information, refer to the World Health Organization's resources on malnutrition.

Frequently Asked Questions

Marasmus results from an overall deficiency of calories and protein, leading to severe wasting and emaciation. Kwashiorkor is primarily a protein deficiency, often with adequate calories, and is characterized by edema (fluid retention).

The main causes include insufficient calorie and protein intake due to poverty, food scarcity, chronic infections (like diarrhea), poor feeding practices, and underlying medical conditions.

Key symptoms are severe muscle and fat wasting, a thin and shrunken appearance, loose and wrinkled skin, and stunted growth. In children, a wizened or 'old man' face is also a common sign.

Diagnosis is based on a physical examination, anthropometric measurements (like weight-for-height), and blood tests to check for specific nutrient deficiencies and underlying issues.

Yes, marasmus is largely preventable through adequate, balanced nutrition, promoting breastfeeding, and addressing underlying factors like poverty, infectious diseases, and poor sanitation.

Treatment involves a phased approach: initial stabilization with rehydration and antibiotics, followed by gradual nutritional rehabilitation using specialized formulas, and finally long-term follow-up and dietary support.

Refeeding syndrome is a life-threatening complication that can occur during the initial stages of treatment for severe malnutrition. It involves dangerous shifts in electrolyte and fluid levels caused by the sudden reintroduction of nutrients.