From the Guidelines
Working up unexplained weight loss involves a systematic medical evaluation to identify the underlying cause, with a significant weight loss defined as more than 5% involuntary weight loss over 3 months, as suggested by the ESPEN guidelines for nutrition screening 2002 1. When evaluating unexplained weight loss, it is crucial to consider the patient's medical history, including recent measurements in medical records, to determine the stability of the condition. Key steps in the workup include:
- Taking a detailed medical history to inquire about eating habits, appetite changes, exercise patterns, stress levels, and other symptoms like fatigue, fever, or digestive issues
- Performing a physical examination
- Ordering laboratory tests, such as complete blood count, comprehensive metabolic panel, thyroid function tests, urinalysis, and inflammatory markers
- Considering additional tests, including screening for diabetes, HIV, tuberculosis, and cancer markers, depending on the patient's risk factors
- Utilizing imaging studies, like chest X-ray, abdominal ultrasound, or CT scans, to evaluate internal organs
- Recommending endoscopic procedures for digestive concerns
- Reviewing the patient's medications, as some can cause weight loss as a side effect, as highlighted in the standards of medical care in diabetes-2022 1 This comprehensive approach is essential because unexplained weight loss can signal various conditions, ranging from psychological disorders to serious illnesses such as cancer, gastrointestinal disorders, endocrine problems, or chronic infections. In cases where deterioration of medical status is associated with significant weight loss, inpatient evaluation should be considered, especially focusing on associations between medication use, food intake, and glycemic status 1.
From the Research
Initial Evaluation
- Unintentional weight loss (UWL) is a common presenting symptom with a wide differential diagnosis, including organic and inorganic causes 2, 3
- The initial approach to evaluating UWL involves understanding the relative prevalence of various causes and the utility of different imaging modalities in diagnosis and management 2
Diagnostic Approach
- Imaging studies, such as radiology exams, are crucial in the diagnosis of UWL, particularly in evaluating for the presence of malignancy 2
- A multi-modality diagnostic approach is essential to illustrate both common and uncommon causes of UWL 2
- Screening tools can be used to identify patients experiencing UWL, and management includes nutrition assessments and diagnosing malnutrition when present 4
Laboratory Tests and Imaging
- Laboratory tests, such as complete blood count (CBC) and liver function tests (LFTs), may be used in the evaluation of patients with UWL, but their utility is limited in certain cases, such as in patients with clinically node-negative breast cancer 5
- Chest X-ray (CXR) is not recommended as a routine screening test for occult metastasis in patients with early-stage breast cancer 5
Management
- Treatment of UWL involves management of underlying causes, and individualized dietary plans with supplementation and/or nutrition support and medications for appetite stimulation may be considered 4
- Close follow-up is warranted for patients who do not have a diagnosis after comprehensive workup, as up to a quarter of patients may not have a diagnosis 3