Unpacking Malnutrition: What is the disease due to malnutrition called?

October 13, 2025 •

4 min read

Globally, the World Health Organization reports that malnutrition in all its forms affects people in every country, encompassing undernutrition, overnutrition, and micronutrient imbalances. To understand the severe health issues it causes, it is crucial to know that there is not a single answer to the question, "What is the disease due to malnutrition called?", but a range of conditions.

Quick Summary

Malnutrition leads to various health conditions, from severe protein-energy deficiencies like marasmus and kwashiorkor to specific vitamin and mineral imbalances. The specific disease manifestation depends on the type and severity of the nutritional deficit or excess.

Key Points

Not a Single Disease: Malnutrition is a broad term for deficiencies, excesses, or imbalances of nutrients, resulting in various diseases, not a single one.
Kwashiorkor vs. Marasmus: Kwashiorkor is severe protein deficiency, causing fluid retention (edema), while marasmus is an overall calorie and protein deficiency, causing severe emaciation.
Micronutrient Deficiencies: A lack of specific vitamins and minerals, like iron (anemia) or vitamin C (scurvy), can cause distinct health conditions.
Causes are Multifaceted: Malnutrition can result from poverty, food scarcity, chronic diseases, mental health issues, and limited nutritional knowledge.
Prevention is Key: A balanced diet rich in varied foods, supplementation when necessary, and addressing underlying social issues are crucial for preventing malnutrition.

Defining Malnutrition: More Than Just a Single Disease

Malnutrition is not a singular disease but a broad term describing deficiencies, excesses, or imbalances in a person's intake of energy and nutrients. This multifaceted condition manifests in several forms, which is why naming just one disease is inaccurate. The consequences are wide-ranging, from life-threatening conditions primarily seen in developing countries to diet-related noncommunicable diseases (NCDs) more common in affluent nations. Understanding the different types of malnutrition is key to recognizing and addressing the specific health problems that arise from it.

The Major Forms of Malnutrition

The two main categories of malnutrition are undernutrition and overnutrition.

Undernutrition: The type most people associate with malnutrition, characterized by a deficiency of nutrients and/or calories. This can lead to visible wasting of fat and muscle, but a person can also be overweight and undernourished if their diet lacks crucial vitamins and minerals.
Overnutrition: This results from excessive consumption of energy and nutrients, leading to overweight, obesity, and NCDs like heart disease and diabetes.
Micronutrient-Related Malnutrition: This category includes deficiencies or excesses of specific vitamins and minerals, which can have severe consequences for proper growth and development.

Protein-Energy Malnutrition: Kwashiorkor vs. Marasmus

Protein-energy malnutrition (PEM) represents a spectrum of severe conditions resulting from a long-term deficiency of total energy intake, protein, or both. The two most severe forms are Kwashiorkor and Marasmus, though mixed forms also exist.

Kwashiorkor: The "Edematous Malnutrition"

Named from the Ga language meaning "the sickness the baby gets when the new baby comes," Kwashiorkor typically affects children after they are weaned from breast milk and moved to a low-protein, high-carbohydrate diet. A key feature is peripheral pitting edema (swelling) caused by fluid retention, which can obscure muscle wasting and make a child appear bloated. Other signs include skin lesions, thinning hair with pigment loss, and an enlarged, fatty liver.

Marasmus: The "Wasting Syndrome"

Marasmus, derived from the Greek word for "withering," results from an extreme and prolonged deficiency of all macronutrients: proteins, carbohydrates, and fats. The body, starved of energy, consumes its own tissues, leading to severe emaciation and a distinctly skeletal appearance. This form is common in infants and young children. Symptoms include muscle wasting, depleted fat stores, loose skin folds, and a prominent skeleton, which can give the face an aged or wizened look. Unlike Kwashiorkor, edema is absent in pure marasmus.

Comparison of Kwashiorkor and Marasmus


Feature	Kwashiorkor	Marasmus
Primary Deficiency	Protein deficiency, often with adequate calorie intake.	Total energy (calories) and protein deficiency.
Appearance	Edema (swelling), distended abdomen, but limbs can appear emaciated.	Severely emaciated, wasted, with noticeable loss of muscle and fat.
Key Signs	Skin lesions, hair discoloration, fatty liver.	Loose, wrinkled skin; ribs and joints are prominent.
Immune Response	Severely compromised, increasing risk of infection.	Also compromised, increasing infection risk.
Common Age	Often affects children around 18 months to 5 years, after weaning.	More common in infants and very young children.

Diseases from Micronutrient Deficiencies

Beyond PEM, a lack of specific vitamins and minerals can trigger distinct diseases. Globally, iron, vitamin A, and iodine are the most common deficiencies.

Diseases caused by micronutrient deficiencies:

Iron Deficiency Anemia: A lack of iron, essential for red blood cell production, leads to symptoms like fatigue, weakness, pale skin, and shortness of breath.
Scurvy: Caused by a severe lack of vitamin C, leading to swollen and bleeding gums, easy bruising, joint pain, and poor wound healing.
Rickets: A condition in children causing bones to soften and weaken, often resulting in bowed legs and other skeletal deformities due to a lack of vitamin D, calcium, or phosphate. The adult equivalent is osteomalacia.
Pellagra: Results from a severe deficiency of niacin (vitamin B3), characterized by the "4 Ds": dermatitis, diarrhea, dementia, and if untreated, death.
Beriberi: Caused by a thiamine (vitamin B1) deficiency, which affects the cardiovascular or nervous systems. Wet beriberi affects the heart, while dry beriberi impacts nerves.
Goiter: The enlargement of the thyroid gland, often caused by a lack of iodine, which is needed to produce thyroid hormones.

Causes, Symptoms, and Prevention

Multiple factors contribute to the development of malnutrition, from societal issues like poverty and food insecurity to individual health conditions. Chronic illnesses, mental health disorders, and malabsorption issues can all play a role. General symptoms of undernutrition include unintentional weight loss, reduced appetite, fatigue, weakness, and delayed wound healing. In children, this often presents as faltering growth and behavioral changes.

Prevention involves a multi-pronged approach:

Eat a varied and balanced diet: This is the best way to ensure adequate intake of macronutrients, vitamins, and minerals. Include plenty of fruits, vegetables, whole grains, and lean proteins.
Supplementation and fortification: In cases of known deficiencies or poor dietary intake, supplements or fortified foods can be effective.
Public health initiatives: Addressing the root causes through poverty reduction, nutritional education, and improving access to clean water and sanitation is crucial, especially in vulnerable populations. The World Health Organization is a key player in promoting these efforts.

Conclusion

In summary, asking "what is the disease due to malnutrition called?" does not have a single answer because malnutrition is a spectrum of conditions. The specific disease depends on whether there is an overall calorie deficit, a protein shortage, or a lack of certain vitamins and minerals. From the devastating protein-energy malnutrition seen in marasmus and kwashiorkor to specific micronutrient deficiencies like scurvy and rickets, the outcomes can be severe if not addressed. Early intervention, a balanced diet, and effective treatment are critical for recovery and for mitigating the long-term impacts on health and development. For more in-depth information, resources from the World Health Organization can be a valuable guide.

Frequently Asked Questions

Yes, it is possible to be both overweight and undernourished. This happens if a diet consists of excess calories but lacks sufficient micronutrients like vitamins and minerals, leading to a condition known as overnutrition alongside micronutrient undernutrition.

Marasmus typically causes severe wasting and emaciation, with visible loss of fat and muscle, resulting in a shrunken appearance. Kwashiorkor, in contrast, is characterized by fluid retention, causing swelling and a bloated belly that can mask muscle wasting.

Refeeding syndrome is a potentially life-threatening complication that can occur during the reintroduction of food to a severely undernourished person. The body's metabolism shifts rapidly, causing dangerous electrolyte imbalances that require careful medical supervision to manage.

Diagnosis of malnutrition typically involves a physical exam to observe signs like wasting or edema, measurements of height and weight (or arm circumference), and blood tests to identify specific nutrient deficiencies. A dietary and medical history is also essential.

Yes, older adults are at increased risk due to factors like reduced mobility, decreased appetite, and certain medical conditions that can interfere with nutrient absorption. Approximately half of older adults in hospitals or long-term care facilities may not consume enough calories.

Scurvy is caused by a severe deficiency of vitamin C (ascorbic acid). This is typically due to a diet lacking fresh fruits and vegetables. Since humans cannot produce their own vitamin C, it must be obtained through diet.

Treatment for malnutrition depends on its severity. Severe cases require supervised medical care, often involving specialized therapeutic foods or formulas. Less severe cases can be managed with nutritional supplements and dietary adjustments to ensure a balanced intake of all essential nutrients.