Malnutrition
Educational information. Individual clinical review of this presentation by Dr. Ehsan is not yet documented. It does not replace personal medical evaluation.
Source: MedlinePlus, National Library of Medicine. Read the original source
MedlinePlus data edition September 26, 2026. Imported September 27, 2026. These dates do not indicate a new clinical review of the article.
What is malnutrition?
Malnutrition means that your body isn't getting enough calories or the right balance of nutrients to stay healthy. This can happen if you don't get enough protein, carbohydrates, and fats, eat too much unhealthy food, or don't get the vitamins and minerals your body needs.
Malnutrition can affect people of all ages, but children, older adults, and people with chronic (long-term) health problems have a higher risk.
What are the types of malnutrition?
Most people think of undernutrition with malnutrition. But malnutrition can refer to undernutrition, overnutrition, or an imbalance of nutrients.
Types of malnutrition include:
- Protein-energy undernutrition, also called macronutrient undernutrition, happens when your body doesn't get enough protein or calories from food. Two serious forms of this are kwashiorkor and marasmus.
- An imbalanced nutritional status occurs when you are not getting the right mix of nutrients. You may get enough calories, but not enough vitamins or minerals.
- Vitamin deficiency diseases happen when your body doesn't get enough of certain vitamins. Without the right vitamins, your body cannot stay healthy and may develop specific diseases. For example, scurvy can develop from too little vitamin C, rickets from too little vitamin D, and anemia from too little iron or vitamin B12.
- Failure to thrive occurs when children don't gain weight or grow as expected. This may be due to not getting enough food, trouble absorbing nutrients, or other health problems.
- Overnutrition can occur when your body gets too many calories or nutrients. This may lead to obesity or other health issues.
What causes malnutrition?
Malnutrition may occur for many reasons, including:
- An unbalanced diet that lacks variety or specific nutrients.
- Some medical issues, which could include malabsorption syndromes, dementia, eating disorders, depression, alcohol use disorder (AUD), or cancer.
- Problems with swallowing, digestion, or dental issues.
- Certain medicines that affect how food tastes and smells.
- Not being able to get food or cook due to things such as chronic illness, mobility issues, or low income.
Who is at risk for developing malnutrition?
Malnutrition can affect anyone, but some people have a higher risk than others. This includes people who:
- Don't have enough knowledge about nutrition
- Don't have access to a variety of food
- Are older adults or children
- Have a low income
- Have a chronic (long-term) illness
What are the symptoms of malnutrition?
The symptoms of malnutrition can vary. You may have no symptoms, but if you do, they may include:
- Fatigue and weakness
- Dizziness
- Losing weight without trying
- Low body weight
- Slow growth or development in children
- Frequent infections or slow healing
- Dry skin or brittle hair and nails
- Swelling in the legs, feet, or belly
How is malnutrition diagnosed?
To check for malnutrition, your provider may:
- Do a nutritional screening, which may include questions about weight loss, changes in your appetite, and your ability to eat.
- Do a physical exam and order blood tests to check for signs that you don't have enough nutrients.
- Refer you to other providers that specialize in nutrition, such as a dietician.
What are the treatments for malnutrition?
Treatment for malnutrition may include improving your diet, replacing missing nutrients, and treating the underlying cause.
Can malnutrition be prevented?
To help prevent malnutrition, eat a healthy diet with many different foods. Talk with your provider if you are worried about your diet, weight loss, or your child's growth.
Symptoms, tests and care options
Further reading selected by MedlinePlus. Links open the original organizations’ websites.
- Albumin Blood Test · National Library of Medicine
- Chymotrypsin in Stool · National Library of Medicine
- How an RDN Can Help with Malnutrition · Academy of Nutrition and Dietetics
- How to Spot and Talk about Symptoms That Could Mean You're Malnourished · American Society for Parenteral & Enteral Nutrition
- Prealbumin Blood Test · National Library of Medicine
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