Your body needs calories, protein, and overall general nutrients to function. Without adequate nutrition, your muscles waste away, your bones become brittle, and your thinking become foggy.

Calories are units of energy your body needs to function. Your body also needs a large amount of protein. Without enough protein, you may not be able to easily heal injuries or wounds.

When you don’t consume enough nutrients, your body becomes malnourished. One type of malnourishment is protein-energy undernutrition.

Protein-energy undernutrition is sometimes called protein-energy malnutrition. You have this if your body has a severe calorie or protein deficiency. This can occur if you don’t consume the amount of calories and protein your body needs to function.

Protein-energy undernutrition doesn’t occur due to short-term illnesses. It’s more likely due to malnutrition over a long period.

Two main types of this undernutrition are marasmus and kwashiorkor. Keep reading to learn more about these conditions.


Undernutrition can occur for multiple reasons. Food resources may be unavailable, or you may have a condition that makes it difficult to eat, absorb nutrition, or prepare food. Drinking too much alcohol can also lead to undernutrition.

The symptoms of undernutrition include:

  • fatigue
  • difficulty staying warm
  • a lower body temperature
  • diarrhea
  • reduced appetite
  • a lack of emotion
  • irritability
  • weakness
  • slower breathing
  • numbness or tingling of the hands and feet
  • dry skin
  • hair loss
  • bruises


Marasmus occurs more often in young children and babies. It leads to dehydration and weight loss. Starvation is a form of this disorder. The symptoms of marasmus include:

  • weight loss
  • dehydration
  • chronic diarrhea
  • stomach shrinkage

You’re at an increased risk for marasmus if you live in a rural area where it’s difficult to get food or an area that has a food shortage. Babies, including babies who aren’t breast-fed, young children, or older adults also have an increased risk for marasmus.

Learn more: What you should know about marasmus »


Kwashiorkor occurs in people who have a severe protein deficiency. Children who develop kwashiorkor are often older than children who develop marasmus. Having a diet that’s mainly carbohydrates can lead to this condition.

The symptoms of kwashiorkor include:

  • edema, or puffy or swollen appearance due to fluid retention
  • bulging of the abdomen
  • an inability to grow or gain weight

You’re at an increased risk for kwashiorkor if you live in a rural area where there’s limited access to protein-rich foods. Children who have been weaned off of breast milk are also at an increased risk if they don’t have access to protein-rich foods.

Marasmus symptomsKwashiorkor symptoms
weight lossan inability to grow or gain weight
dehydrationedema, or swelling of the hands and feet
stomach shrinkagestomach bulging

Causes of marasmus and kwashiorkor

The main cause of both of these conditions is a lack of access to food. Some things that may affect a person’s access to food include:

  • famine
  • a caregiver’s inability to get food due to lack of transportation or a physical inability
  • living in poverty

Other things that may lead to these conditions include:

  • having an eating disorder
  • lacking education about dietary needs
  • taking medication that interferes with the absorption of nutrients
  • having a medical condition that increases your body’s need for calories


Your doctor will first look at physical symptoms. They’ll also ask questions about your access to food, any history of eating disorders, and medications you’re taking. They may also ask about your current mental state or mood.

They may do a skin test to determine if your immune system is working correctly. They may take a stool sample to rule out other issues related to diarrhea if diarrhea is a symptom. Your doctor may also test your urine or your blood to help identify a nutrition deficiency.


Both conditions are treatable by slowly increasing calorie intake through several, small meals. Your doctor may add liquid protein supplements if you have problems digesting food.

Doctors often recommend multivitamin supplements and may prescribe medications to improve appetite. If the symptoms are severe, hospitalization may be necessary.


Seeking help as soon as possible is important for recovery and long-term survival. Children who develop kwashiorkor may not reach their full potential for height. If a child doesn’t get treatment early on, they may develop permanent mental and physical disabilities. Both conditions can lead to death if they’re left untreated.