Which disease is caused by malnutrition? A comprehensive overview

December 5, 2025 •

4 min read

According to the World Health Organization, nearly half of all deaths in children under five are linked to undernutrition. A wide range of diseases and chronic conditions result from an imbalance, deficiency, or excess of nutrients, answering the question: which disease is caused by malnutrition?.

Quick Summary

Malnutrition leads to numerous illnesses, including protein-energy malnutrition like kwashiorkor and marasmus, as well as specific micronutrient deficiencies causing conditions such as scurvy, rickets, and anemia. These conditions severely impact physical and cognitive development, especially in children, and affect immune function, wound healing, and organ health.

Key Points

Kwashiorkor: A severe protein deficiency caused by malnutrition, often seen in children after they are weaned, leading to a distended abdomen and muscle wasting.
Marasmus: A severe lack of both calories and protein resulting in extreme emaciation, growth stunts, and depleted fat and muscle mass.
Scurvy: This disease is directly caused by a vitamin C deficiency, resulting in swollen gums, poor wound healing, and fatigue.
Rickets: Caused by a lack of vitamin D, calcium, or phosphate, leading to softened bones and skeletal deformities in children.
Anemia: Often caused by a deficiency in iron, but also B12 or folate, leading to fatigue, weakness, and pale skin.
Overnutrition: Malnutrition can also mean an excess of calories, leading to obesity, diabetes, and heart disease.
Weakened Immunity: Nutrient deficiencies impair the immune system, increasing susceptibility to infections and delaying recovery.
Irreversible Damage: Severe malnutrition in early childhood can cause permanent cognitive impairment and stunted growth.

Understanding the Link Between Malnutrition and Disease

Malnutrition encompasses deficiencies, excesses, or imbalances in a person's intake of energy and nutrients. While many associate it with undernutrition and starvation, it also includes overnutrition, leading to obesity and related chronic illnesses. The specific disease caused by malnutrition depends on which nutrients are lacking or consumed in excess. A diet that lacks essential vitamins, minerals, and macronutrients disrupts vital bodily functions, weakens the immune system, and can lead to a cascade of severe health problems.

Protein-Energy Malnutrition (PEM)

PEM is one of the most common forms of severe malnutrition, particularly affecting infants and young children in developing countries. It results from a severe deficiency of both protein and calories. Two prominent diseases fall under this category:

Kwashiorkor: This form is primarily a severe protein deficiency, though calorie intake may be relatively normal. It often occurs when a child is weaned from protein-rich breast milk and fed a high-carbohydrate, low-protein diet. Symptoms include a distended abdomen (due to edema), muscle wasting, an enlarged liver, and changes in hair color and texture. The immune system is also severely weakened, increasing susceptibility to infections.
Marasmus: This condition is a severe deficiency of both calories and protein, leading to drastic weight loss and muscle wasting. Infants with marasmus appear emaciated, with a skeletal-like appearance and little to no body fat. Marasmus impairs growth and development significantly.

Micronutrient Deficiencies and Resulting Diseases

Micronutrient deficiencies, or a lack of crucial vitamins and minerals, can cause a variety of specific diseases. Here are some of the most notable examples:

Scurvy: This disease is caused by a severe lack of vitamin C, essential for collagen formation, wound healing, and immune function. Historically, it was common among sailors. Symptoms include fatigue, swollen and bleeding gums, joint pain, and skin rashes.
Rickets: A deficiency in vitamin D, calcium, or phosphate can cause rickets, which leads to weakened and softened bones in children. This can result in skeletal deformities, such as bowed legs, and impaired growth. Osteoporosis, a similar condition causing weakened bones, can affect adults with long-term calcium and vitamin D deficiencies.
Anemia: Iron deficiency is the most common nutritional deficiency worldwide and causes anemia. Anemia is characterized by a low number of red blood cells or hemoglobin, leading to fatigue, weakness, pale skin, and shortness of breath. Deficiencies in vitamin B12 and folate can also cause specific types of anemia.
Goiter: This condition is the enlargement of the thyroid gland, often caused by a lack of iodine, which is necessary for producing thyroid hormones. Without enough iodine, the thyroid grows in an effort to compensate, causing a visible swelling in the neck.
Xerophthalmia and Night Blindness: Vitamin A deficiency is a major cause of preventable childhood blindness globally. Initial symptoms include night blindness, and if left untreated, it can progress to xerophthalmia, a condition causing eye and corneal damage that can lead to permanent blindness.

Comparison of Major Malnutrition-Related Diseases


Feature	Kwashiorkor	Marasmus	Scurvy	Rickets
Primary Nutrient Lack	Protein	Calories and Protein	Vitamin C	Vitamin D, Calcium, Phosphate
Physical Appearance	Bloated abdomen, swollen face, muscle wasting	Emaciated, severe muscle and fat wasting	Skin lesions, bleeding gums	Bowed legs, skeletal deformities
Typical Patient Profile	Weaned children, older than those with marasmus	Infants and very young children	Individuals with limited access to fruits/vegetables	Children with low sun exposure/intake
Key Symptoms	Edema, hair changes, skin problems	Severe weight loss, lethargy, stunted growth	Fatigue, poor wound healing, joint pain	Bone pain, skeletal weakness, growth issues
Immune Impact	Weakened immune system, increased infection risk	Impaired immune system function	Depressed immune response	Not a primary immune issue, but overall health is poor

The Broader Impact of Malnutrition

Beyond these specific diseases, malnutrition can have wide-ranging and long-lasting effects on a person's overall health and development. These include:

Weakened Immune System: Nutrient deficiencies compromise the immune system, making individuals more vulnerable to infections and diseases.
Impaired Cognitive Development: Malnutrition, especially in early life, can cause irreversible damage to the brain, leading to delayed mental development and potential intellectual disability.
Delayed Growth: Chronic undernutrition, known as stunting, results in low height-for-age and prevents children from reaching their full physical potential.
Increased Morbidity and Mortality: Malnourished individuals have a higher risk of complications from other illnesses and a significantly higher mortality rate.
Negative Economic Consequences: Malnutrition increases healthcare costs, reduces productivity, and slows economic growth, perpetuating a cycle of poverty and ill-health.

Prevention and Treatment Strategies

Treating diseases caused by malnutrition requires addressing the underlying nutritional issues. For severe cases like marasmus and kwashiorkor, treatment often involves carefully reintroducing nutrient-dense foods under medical supervision. Addressing specific vitamin and mineral deficiencies may require targeted supplementation, alongside dietary adjustments. Prevention is crucial and involves improving access to and education about nutritious food, especially for vulnerable populations like children and pregnant women. Global and local efforts focus on food fortification programs and sustainable food systems to combat malnutrition in all its forms. For more on global nutritional strategies, see the World Health Organization's nutrition information.

Conclusion

Malnutrition is not a single disease but a complex health issue that is a root cause for many other severe conditions. From life-threatening protein-energy malnutrition diseases like kwashiorkor and marasmus to specific vitamin deficiency diseases like scurvy and rickets, the impact is profound. By understanding which disease is caused by malnutrition, we can better appreciate the critical role of balanced nutrition in maintaining overall health, preventing illness, and ensuring healthy development throughout life. Addressing malnutrition requires concerted effort on both an individual and global scale to ensure everyone has access to the essential nutrients they need to thrive.

Frequently Asked Questions

Yes, malnutrition is a primary cause of anemia. An inadequate intake of essential nutrients like iron, vitamin B12, and folate prevents the body from producing enough healthy red blood cells, leading to fatigue and weakness.

Kwashiorkor is primarily a protein deficiency, characterized by fluid retention (edema) and a swollen abdomen, while marasmus results from a severe deficiency of both protein and calories, causing extreme muscle wasting and emaciation.

Yes, it is possible to be overweight and malnourished. This can happen if a diet is high in calories but lacks essential vitamins and minerals, a condition sometimes called 'hidden hunger.' The overconsumption of poor-quality, energy-dense foods can lead to overnutrition-related health issues.

Yes, malnutrition, especially in early life, can severely impact cognitive development. It can lead to delayed motor skills, poor mental development, and in severe cases, permanent cognitive deficits.

Night blindness is caused by a vitamin A deficiency. Vitamin A is crucial for the function of the retina and the production of rhodopsin, a pigment needed for low-light vision.

While osteoporosis is not exclusively caused by malnutrition, it can be a direct result of long-term deficiencies in calcium and vitamin D, both of which are essential for strong bones.

Malnutrition significantly weakens the immune system. Nutrient deficiencies reduce the body's ability to produce immune cells and antibodies, making individuals more susceptible to infections and slower to recover from illnesses.