Unintentional weight loss is a decrease in body weight that is not voluntary. In other words, you did not try to loss the weight by dieting or exercising.

See: Intentional weight loss

Loss of weight

There are many causes of unintentional weight loss. Some are listed below:

• AIDS
• Cancer
• Depression
• Diarrhea that is chronic (lasts a long time)
• Drugs, including amphetamines, chemotherapy drugs, laxatives (when abused), and thyroid medications
• Drug abuse
• Eating disorders, including anorexia nervosa and bulimia
• Hyperthyroidism
• Infection
• Loss of appetite
• Malnutrition
• Manipulative behavior (in children)
• Painful mouth sores, mouth braces, or a loss of teeth that prevent you from eating normally
• Smoking

Note: This list may not be all inclusive

Practice moderation and maintain a balanced diet and exercise program. For weight loss caused by oral or dental problems, see the dentist. For weight loss caused by disease, follow your health care provider's prescribed therapy to treat the cause.

Call your health care provider if:

• An adolescent son or daughter has an unrealistic self-image and seems to be dieting too much.
• You have lost more than 5% of your normal body weight over 6 - 12 months or less, and the weight loss cannot be explained.
• Other symptoms have occurred with the weight loss.

The health care provider will perform a physical exam and measure your weight. You may be asked questions about your medical history and symptoms, including:

• When did the weight loss begin?
• Has the weight loss occurred suddenly or slowly?
• How much weight have you lost?
• Are you eating less?
• Are you eating different foods?
• Are you exercising more?
• Have you been sick?
• Do you have any dental problems or mouth sores?
• Do you have more stress or anxiety than usual?
• Have you vomited? Did you make yourself vomit?
• Do you have more energy lately?
• Are you fainting?
• Do you have occasional uncontrollable hunger with palpitations, tremor, and sweating?
• Have you had a change in vision?
• Do you have increased sensitivity to cold or heat?
• Have you had constipation or diarrhea?
• Do you have increased thirst or are you drinking more?
• Are you urinating more than usual?
• Have you lost any hair?
• What medications/drugs are you taking?
  • Diuretics?
  • Laxatives?
  • Alcohol?
  • Street drugs?
• Do you have severe depression?
• Are you pleased or concerned with the weight loss?

The following tests may be done:

• Nutritional assessment
• Blood tests including a chemistry profile

Psychological counseling may be recommended in cases where anorexia nervosa or depression is the cause of the weight loss. For weight loss caused by a chronic illness, tube feeding may be needed in order to maintain nutrition and prevent edema, poor healing, and muscle wasting.

You may need to see a dietitian for nutritional counseling.

Bistrian BR. Nutritional assessment. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 233.

Noel MB, Thompson M, Wadland Wc, Holtrop JS. Nutrition and family medicine. In: Rakel RE, ed. Textbook of Family Medicine. 7th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 48.