What is the appropriate workup for a patient presenting with weight loss?

From the Guidelines

The appropriate workup for a patient presenting with weight loss begins with a thorough history and physical examination to identify potential causes, with a focus on assessing for cachexia and malnutrition, as these conditions can significantly impact morbidity, mortality, and quality of life 1. When evaluating a patient with weight loss, it is essential to consider the primary features of cachexia, including inadequate nutrient intake, decreased or absent physical activity, and altered metabolism due to a pathological systemic inflammatory response 1. The workup should include:

• A thorough history to assess the amount and timeframe of weight loss, with unintentional loss of more than 5% of body weight over 6-12 months considered significant
• Initial laboratory testing, such as complete blood count, comprehensive metabolic panel, thyroid function tests, urinalysis, and fasting glucose
• Additional first-line tests, including erythrocyte sedimentation rate, C-reactive protein, HIV testing, and a tuberculosis test
• Age-appropriate cancer screenings, including mammography, colonoscopy, and prostate-specific antigen testing
• A nutritional assessment and evaluation for depression or eating disorders, as psychological causes are common
• If malabsorption is suspected, stool studies for fat and pathogens may be warranted The goal of the workup is to identify the underlying cause of weight loss, which could range from malignancy, chronic infection, and endocrine disorders to psychological conditions, and provide optimal nutritional care and supportive measures to prevent further involuntary weight loss and improve quality of life 1. It is crucial to recognize that certain groups of patients are at high risk of developing malnutrition and/or cachexia, such as those with cancer of the head and neck or pancreas, and those having neoadjuvant treatment of gastro-oesophageal cancer 1. By taking a systematic and comprehensive approach to evaluating weight loss, clinicians can provide targeted treatment and improve patient outcomes.

From the Research

Workup for Weight Loss

The workup for a patient presenting with weight loss involves a comprehensive approach to determine the underlying cause.

• History and physical examination are essential in identifying potential causes of weight loss, as they can reveal signs and symptoms that may indicate a specific diagnosis 2, 3.
• Laboratory tests, such as complete blood count, chemistry panel, and ultrasensitive thyroid-stimulating hormone test, can help identify underlying medical conditions that may be contributing to weight loss 4.
• Imaging studies, such as abdominal ultrasonography and computed tomography, may be necessary to evaluate for potential causes of weight loss, particularly in patients with isolated involuntary weight loss 5.
• A fecal occult blood test and upper gastrointestinal studies may also be considered in selected patients to rule out gastrointestinal causes of weight loss 4.

Differential Diagnosis

The differential diagnosis for weight loss is extensive and includes:

• Cancer, particularly of the digestive system 2, 3, 5
• Depression and other psychiatric disorders 2, 3, 4
• Gastrointestinal disorders, such as benign gastrointestinal diseases and dysphagia 2, 4
• Cardiac disorders 4
• Medications that may cause nausea, vomiting, and anorexia 4

Management

Management of weight loss involves treating the underlying medical or psychiatric cause, if possible.

• Nutritional support and environmental modifications may be necessary to support patients with unintentional weight loss 4.
• Close follow-up is warranted in patients who do not have a diagnosis after comprehensive workup, as some cases may remain undiagnosed despite extensive evaluation 2, 3.