Marasmus is severe undernutrition — a deficiency in all the macronutrients that the body requires to function, including carbohydrates, protein and fats. Marasmus causes visible wasting of fat and muscle under the skin, giving bodies an emaciated appearance. It causes stunted growth in children.
Marasmus is a severe form of malnutrition — specifically, protein-energy undernutrition. It results from an overall lack of calories. Marasmus is a deficiency of all macronutrients: carbohydrates, fats, and protein. If you have marasmus, you lack the fuel necessary to maintain normal body functions. People with marasmus are visibly depleted, severely underweight and emaciated. Children may be stunted in size and development. Prolonged marasmus leads to starvation.
Marasmus and kwashiorkor are two different variations of severe protein-energy undernutrition. Marasmus is a deficiency of all macronutrients, while kwashiorkor is a deficiency in protein predominantly. Kwashiorkor occurs in people who may have access to carbohydrates — bread, grains or starches — but lack protein in their diet. Marasmus has a wasted and shriveled appearance, while kwashiorkor is known for causing edema — swelling with fluid, especially in the belly and the face.
Marasmus can affect anyone who lacks overall nutrition, but it particularly affects children, especially infants, who require more calories to support their growing bodies. It is more common in developing countries with widespread poverty and food scarcity, and where parasites and infectious diseases may contribute to calorie depletion. In the developed world, elderly people in nursing homes and hospitals or who live alone with few resources are more at risk.
When the body is deprived of energy from food, it begins to feed on its own tissues — first adipose tissue (body fat) and then muscle. It also begins shutting down some of its functions to conserve energy. Cardiac activity slows down, causing low heart rate, low blood pressure and low body temperature. In some cases, this leads to heart failure. The immune system is also compromised, making undernourished people more prone to infection and illness and slower to recover.
Children with chronic marasmus will not have the physical resources to grow and develop as they should. They may be stunted in size or have developmental delays or intellectual disabilities. These effects can be lasting, even in children who receive treatment. Parts of the digestive system also begin to atrophy from the lack of use. This means that even when people do have food to eat, they might not be able to absorb nutrition from their food effectively. Ironically, marasmus can lead to food aversion.
The main causes affecting all ages include:
Additional causes affecting children include:
Additional causes affecting adults include:
Healthcare providers will begin by physically examining the person’s body. Marasmus has some telltale physical features, the primary one being the visible wasting of fat and muscle. People with marasmus appear emaciated. The loss of fat and muscle under the skin may cause the skin to hang loose in folds. Beyond appearances, healthcare providers will measure the height or length of the person’s body and the circumference of their upper arm.
Healthcare providers use a few different charts to measure a child’s or adult’s weight-to-height ratio against medical standards, depending on their age. Marasmus is defined differently on different charts, but it is always significantly below average. To use a chart more people are familiar with, marasmus would score below a 16 on the BMI (body mass index). The purpose of the scoring is mostly to confirm the diagnosis and rate how severe it is.
Diagnosis primarily relies on body measurements, which are then scored according to different scoring systems for children and adults. Upper arm circumference and height-to-weight ratios help healthcare providers rate the severity of undernutrition. Height-to-age ratios help define growth delays in children. Healthcare providers will usually recognize the type of undernutrition (marasmus) based on physical signs.
The next step will be to take a blood test to identify the secondary effects of marasmus, including specific vitamin, mineral, enzyme and electrolyte deficiencies. This will help determine the child’s or adult’s nutritional needs for refeeding. A complete blood count can also help reveal any infections or diseases that may have contributed to or resulted from marasmus. They may check a stool sample for parasites. Infections will need to be treated separately.
People in treatment for marasmus are at risk of refeeding syndrome, a life-threatening complication that can result when the undernourished body tries to reboot too fast. For this reason, rehabilitation happens in stages. Ideally, people with marasmus should be treated in a hospital setting, under close medical supervision. Healthcare providers who are trained to anticipate and recognize refeeding syndrome can help prevent or correct it by supplementing missing electrolytes and micronutrients.
The first stage of treatment is focused on treating dehydration, electrolyte imbalances and micronutrient deficiencies to prepare the body for refeeding. In many cases, these can all be treated with one formula, REhydration SOlution for MALnutrition (ReSoMal), given orally or through a nasogastric tube. It's also important to keep the person warm to prevent hypothermia and to treat infections, which compromise their meager energy resources. Depending on the individual, it may take several hours to days before they are considered stable enough to begin refeeding.
Refeeding begins slowly with liquid formulas that carefully balance carbohydrates, proteins and fats. For inpatients, healthcare providers prefer tube feeding because it allows for gradual but continuous nutrition. Calories are introduced at about 70% of normal recommended values for the person’s age. Eventually, they may increase to 140% of recommended values to meet the growth requirements of stunted children. This phase may last two to six weeks. During this time, patients gradually progress to more ordinary oral feeding with solid foods.
Since marasmus can recur, a complete treatment protocol includes education and outgoing support for the patient and/or their caregiver before they are discharged. In the developing world, this may mean breastfeeding support, safe drinking water and food preparation guidelines, immunizations and education to prevent widespread diseases. In the developed world, caregivers may need guidance on how to recognize signs of malnutrition in those they care for. The Malnutrition Universal Screening Tool (MUST) can help identify people at risk.
In your own community, you can help prevent marasmus by advocating for the needs of children and elders who may be unable to advocate for themselves, especially those living in hospitals and care homes.
In the global community, preventing marasmus means:
The average time spent in treatment for marasmus is 42 days. After treatment, those who return to a caring environment with the resources they need to maintain good health can generally expect to make a full recovery. Many children appear to catch up on their growth and development deficits, though these long-term outcomes are still being studied. Continuing vitamin and mineral supplementation may help.
A note from Cleveland Clinic
Marasmus results from an overall deficit of calories. Food deprivation is enough to induce it, but its effects are much more complicated than that. That’s because marasmus is not simply hunger — it's a series of progressive adaptations that the body makes to try to survive hunger. Reversing those adaptations to restore overall health will take time and care. But with those resources, people can make miraculous recoveries.
Last reviewed by a Cleveland Clinic medical professional on 06/11/2022.
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