special subjects
Involuntary Weight Loss
Evaluation of Involuntary Weight Loss
Evaluation focuses on detection of otherwise occult causes. Because these are numerous, evaluation must be comprehensive. History of present illnessincludes questions about the amount and time course of weight loss. A report of weight loss may be inaccurate; thus, corroborating evidence should be sought, such as weight measurement in old medical records, changes in size of clothes, or confirmation by family members. Appetite, food intake, swallowing, and bowel patterns should be described. For repeat evaluations, patients should keep a food diary because recollections of food intake are often inaccurate. Nonspecific symptoms of potential causes are noted, such as fatigue, malaise, fevers, and night sweats. Review of systemsmust be complete, seeking symptoms in all major organ systems. Past medical history and social historymay reveal a disorder capable of causing weight loss. Also addressed should be use of prescription medications, over-the-counter medications, recreational drugs, and herbal products. Social history may reveal changes in living situations that could explain why food intake is decreased (eg, loss of loved one, loss of independence or job, loss of communal eating routine). Vital signs are checked for fever, tachycardia, tachypnea, and hypotension. Weight is measured and Diagnosis is calculated. Triceps skinfold thickness and mid upper arm circumference can be measured to General examination should be particularly comprehensive, including examination of the heart, lungs, abdomen, head and neck, breasts, neurologic system, rectum (including prostate examination and testing for occult blood), genitals, liver, spleen, lymph nodes, joints, skin, mood, and affect. Fever, night sweats, generalized lymphadenopathy Bone pain Dyspnea, cough, hemoptysis Inappropriate fear of weight gain in an adolescent or young woman Polydipsia and polyuria Headache, jaw claudication, and/or visual disturbances in an older adult Roth spots, Janeway lesions, Osler nodes, splinter hemorrhages, retinal artery emboli Interpretations of some findings are listed in the table. Abnormal findings suggest the cause of weight loss in about half or more patients, including patients eventually diagnosed with cancer. Although many chronic disorders can cause weight loss, the clinician must not be too quick to assume that an existing disorder is the cause. Although the existing disorder is the likely cause in patients whose condition has remained poorly controlled or is deteriorating, stable patients who suddenly begin losing weight without a worsening of that disorder may have developed a new condition (eg, patients with stable ulcerative colitis may begin losing weight because they developed a colon cancer). When a chronic disease has been stable, do not assume that it is the cause of acute weight loss. Age-appropriate cancer screening (eg, colonoscopy, mammography) is indicated if not previously done. Other testing is done for disorders suspected based on abnormal findings in the history or examination. There are no widely accepted guidelines on other testing for patients without such focal abnormal findings. One suggested approach is to do the following tests: Chest x-ray Urinalysis Complete blood count (CBC) with differential count Erythrocyte sedimentation rate (ESR) or C-reactive protein HIV testing Serum chemistries (serum electrolytes, calcium, hepatic and renal function tests) Thyroid-stimulating hormone (TSH) level Abnormal results on these tests are followed with additional testing as indicated. If all test results are normal and clinical findings are otherwise normal, extensive further testing (eg, CT, MRI) is not recommended. Such testing is very low yield and can be misleading and harmful by revealing incidental, unrelated findings. Such patients should be taught how to ensure adequate caloric intake and have a follow-up evaluation in about 1 month that includes a weight measurement. If patients have continued to lose weight, the entire history and physical examination should be repeated because patients may share important, previously undisclosed, information, and new, subtle physical abnormalities may then be detected. If weight loss continues and all other findings remain normal, further testing (eg, CT, MRI) should be considered. 