Malnutrition will often be noticeable to the doctor’s trained eye before it causes significant abnormalities in laboratory test results. During physical examinations, doctors will evaluate the patient’s overall appearance: their skin and muscle tone, the amount of body fat they have, their height and weight, body mass index and their eating habits. In the case of infants and children, doctors will assess development and rate of growth.
If there are signs of malnutrition, the doctor may request general laboratory screening tests to evaluate a patient’s blood cells and organ function. Additional individual tests may be requested to look for specific vitamin and mineral deficiencies. If general malnutrition and/or specific deficiencies are diagnosed, then laboratory testing may be used to monitor the response to therapy. A person who has malnutrition because of a chronic disease may need to have his or her nutritional status monitored on a regular basis.
Hospitalised patients should have their nutritional status assessed at the time of admission. This is usually done using a nutritional screening tool such as the MUST (Malnutrition universal screening tool) which involves assessing the patient’s body mass index (BMI), recent weight loss and presence of acute illness. If screening suggests that the individual is malnourished or at risk of developing malnourishment they should have a more detailed nutritional assessment which may include dietetic assessment and laboratory tests. If the results of these tests indicate possible nutritional deficits, patients may be provided nutritional support prior to a surgery or procedure and be monitored regularly during recovery. Nutritional support encompasses oral nutritional support (providing nutritional supplements to be taken by mouth), enteral nutrition (feeding through a tube directly into the gut) and parenteral nutrition (feeding into a vein).
Laboratory tests may include:
For general screening and monitoring:
For nutritional status and deficiencies:
The results of these laboratory tests should always be considered in clinical context because they can be influenced by many conditions other than malnutrition. Laboratory tests are not a substitute for clinical assessment by a health professional.
Imaging and radiographic scans may be requested to help evaluate the health of internal organs and the normal growth and development of muscles and bones. These tests may include: