Does marasmus cause edema? The key differences in severe malnutrition

November 17, 2025 •

3 min read

Affecting millions of children globally, severe acute malnutrition manifests in different forms, and while some types cause swelling, the answer to does marasmus cause edema? is no. The absence of edema is, in fact, one of the primary features that distinguish marasmus from another severe malnutrition condition called kwashiorkor.

Quick Summary

Marasmus is a form of severe malnutrition defined by extreme muscle and fat wasting, leading to an emaciated appearance, and notably lacks edema. Edema is instead the hallmark of kwashiorkor, a different form of severe malnutrition.

Key Points

No Edema in Marasmus: Marasmus is defined by the absence of edema, whereas edema is the primary characteristic of kwashiorkor.
Wasting vs. Swelling: Marasmus causes extreme wasting of muscle and fat due to a total calorie and protein deficit, leading to an emaciated appearance. Kwashiorkor causes swelling due to fluid retention.
Different Underlying Deficiencies: Marasmus results from a deficiency of all macronutrients, while kwashiorkor is a severe protein deficiency.
Hypoalbuminemia Drives Edema: The edema in kwashiorkor is caused by low levels of the protein albumin in the blood, which alters fluid balance.
Refeeding Risks: Both conditions require careful nutritional rehabilitation to avoid refeeding syndrome, a potentially fatal complication.
The Hybrid Form: Some children suffer from marasmic-kwashiorkor, a combination of both wasting and edema, blurring the classic distinction.

Marasmus vs. Kwashiorkor: Why the Difference Matters

Marasmus and kwashiorkor represent two distinct forms of Severe Acute Malnutrition (SAM), each resulting from different underlying dietary deficiencies. The crucial differentiator between them is the presence or absence of edema, or fluid retention. A person with marasmus does not experience edema; their condition is characterized by profound wasting, meaning the loss of muscle and subcutaneous fat. This occurs because the body, starved of overall calories and protein, breaks down its own tissues for energy.

Conversely, kwashiorkor is defined by the presence of bilateral pitting edema. This fluid buildup, often visible in the ankles, feet, and face, can mislead an observer about the severity of malnutrition, as the swelling can mask the true weight loss. Edema in kwashiorkor results from a severe deficiency of protein, which leads to a decrease in serum albumin levels. Albumin is a protein crucial for maintaining oncotic pressure in the bloodstream. When albumin levels are too low, fluid leaks from the blood vessels into surrounding tissues, causing the characteristic swelling.

The Physiological Response in Marasmus

In marasmus, the body's physiological response is one of survival and adaptation to chronic, severe energy deprivation.

The body's metabolic rate is significantly reduced to conserve energy.
It mobilizes all available energy stores, first from fat and then from muscle, which leads to the visible signs of emaciation.
The hormonal profile shifts, with decreased insulin and increased growth hormone and cortisol, further facilitating the breakdown of tissues.
The immune system is severely compromised, increasing the risk of infections, which is a major cause of death.
Other symptoms include hypothermia, hypoglycemia, and bradycardia due to the body shutting down non-essential functions.

The Unique Pathophysiology of Kwashiorkor

Kwashiorkor's pathophysiology is more complex than a simple protein deficiency, though that is a primary driver. Key factors include:

Severe protein deficit with comparatively adequate carbohydrate intake.
Hypoalbuminemia, which is the direct cause of the peripheral edema.
An imbalance of antioxidants and oxidative stress.
Gut microbiome alterations.
These factors lead to impaired hepatic protein synthesis, resulting in a fatty, enlarged liver.

The Overlap: Marasmic-Kwashiorkor

It is important to note that the distinction between marasmus and kwashiorkor is not always clear-cut. A child may present with symptoms of both, a condition referred to as marasmic-kwashiorkor. This hybrid form is characterized by the severe wasting of marasmus combined with the bilateral pitting edema of kwashiorkor. Its presence highlights that malnutrition is a spectrum, not a rigid set of categories, and that both calorie and protein deficiencies can coexist.

Comparison of Marasmus and Kwashiorkor


Feature	Marasmus	Kwashiorkor
Primary Deficiency	All macronutrients (calories, protein, fat)	Primarily protein
Edema	Absent; non-edematous malnutrition	Present; edematous malnutrition
Body Appearance	Severely emaciated, 'skin and bones'	Edema can mask wasting; 'moon face', distended belly
Subcutaneous Fat	Severely depleted	Often retained, though limbs may be thin
Muscle Wasting	Extreme wasting of muscle tissue	Present, but often hidden by swelling
Liver	Normal size	Enlarged (fatty liver)
Appetite	Often a ravenous appetite	Poor appetite or anorexia
Skin/Hair	Dry, loose, wrinkled skin	Dermatitis, skin lesions, hair changes

Conclusion

In conclusion, the presence of edema is the defining clinical difference between kwashiorkor and marasmus. While both are life-threatening forms of severe acute malnutrition, marasmus is non-edematous and marked by severe energy wasting, a result of total calorie deprivation. Edema, the characteristic fluid retention seen in kwashiorkor, arises from severe protein deficiency. Understanding this key distinction is vital for accurate diagnosis and for implementing the appropriate nutritional rehabilitation protocol, which differs slightly for each condition.

For more information on the clinical management of these conditions, refer to comprehensive medical guidelines like those published by the National Center for Biotechnology Information (NCBI) on the Recognition and Management of Marasmus and Kwashiorkor.

Frequently Asked Questions

The main difference is the presence of edema. Marasmus is characterized by severe wasting (extreme weight loss and muscle depletion) without edema, while kwashiorkor is defined by edema (swelling due to fluid retention), particularly in the feet, ankles, and face.

Kwashiorkor causes edema due to a severe deficiency of protein, which leads to low levels of albumin in the blood. This reduces the blood's oncotic pressure, causing fluid to leak into body tissues. Marasmus, involving a deficit of all macronutrients, causes the body to break down fat and muscle tissue for energy instead of retaining fluid.

Common symptoms of marasmus include severe weight loss, an emaciated or 'skin and bones' appearance, visible loss of fat and muscle, a disproportionately large head, sunken eyes, dry and wrinkled skin, and often a ravenous appetite.

Yes, it is possible for a person to have a hybrid form called marasmic-kwashiorkor. In this condition, the patient exhibits both the severe wasting characteristic of marasmus and the bilateral pitting edema found in kwashiorkor.

Marasmus is primarily a deficiency of all macronutrients, including total calories, carbohydrates, and fats, in addition to protein. This total energy deficit is what drives the body to consume its own muscle and fat stores.

The prognosis for marasmus is generally better than for kwashiorkor, assuming proper treatment is received. The presence of edema and other systemic complications like a fatty liver make kwashiorkor a more dangerous condition, though both are severe and potentially fatal.

Diagnosis of marasmus is primarily based on anthropometric measurements and physical examination. Healthcare providers look for severe weight loss, low weight-for-height scores, reduced mid-upper arm circumference, and signs of extreme muscle and fat wasting.