Womens Health

Involuntary Weight Loss Evaluation

Frederick R. Jelovsek MD

Involuntary weight loss is defined as a decrease of at least 5% of body weight in a 6 month period that isn't due to dieting, diuretic use or medical diseases known to affect weight. If you are overweight, you may wish for this, but if you or a friend are losing weight unintentionally, it needs to be diagnosed so there is not an increased risk of disease or dying. Many times, involuntary weight loss is associated with elderly adults but it is possible to happen to anyone. Up to 8% of patients presenting to primary care physicians complain of weight loss. In 25% of those, no cause for the weight loss is ever found.

A recent review paper, Bianchi A, Toy EC, Baker B III: The evaluation of involuntary weight loss. Prim Care Update Ob/Gyns 1998;5:263-267, categorized three basic causes of weight loss:

  • decreased intake - the most common cause, most often in teenagers and elderly adults
  • increased fluid-nutrient loss - associated with malabsorption and diabetes
  • excess metabolic demand - malignancies often associated with gastrointestinal tract, genitourinary system and breast

It is important to document the fact that weight loss is taking place. Believe it or not, many who complain of involuntary weight loss have no weight change by objective documentation. There are some factors, however, that are diagnostic predictors of underlying illness:

  1. recent change in cough
  2. nausea or vomitting
  3. a 20 pack-year history of smoking
  4. a recent change in appetite
  5. a decrease in activity due to fatigue
  6. an abnormality on physician's physical examination

If the cause of weight loss is not obvious, the physician should check initial laboratory tests including CBC, HIV, blood chemistry, urinalysis, thyroid function, chest xray and routine recommended cancer screening. The following specific diseases may be present.

Diseases Causing Involuntary Weight Loss

Category examples

Decreased intake

gastrointestinal disease peptic ulcer, cholelithiasis
malignancy G.I., ovarian
eating disorders anorexia, bulemia nervosa
hyperemesis gravidarum
poor dentition
social isolation or poverty
depression or dementia
substance abuse alcohol, cocaine, amphetamines
medications digitalis, theophylline, procainamide
age-related changes
infection HIV
systemic diseases

Increased fluid- nutrient loss

persistent diarrhea
recurrent vomitting
fistulous drainage
medications cholestyramine, laxatives
pancreatic insufficiency
infection giardiasis
inflammatory bowel disease Crohn's disease, diverticultits
uncontrolled diabetes mellitus

Excess metabolic demand

tumor of adrenal gland pheochromocytoma
malignancy disseminated, metastatic
fever and/or infection malaria, TB, HIV
manic or anxiety states
trauma and burns
excess exercise
systemic disease

In one fourth of patients with this problem, no diagnosis will be found. Another one fourth will have malignancies. Of the remaining 50%, half will have depression or some psychiatric disease and half will have a medical cause. Although sometimes malignancies are found as a cause of involuntary weight loss, most of the time there are specific treatments that are successful for the remaining people without malignancies.

Other Related Articles

New Diabetes Diagnostic Categories
Eating Disorders and Their Medical Symptoms
Mental Health Diagnosis

Login to comment

Post a comment