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, chemotherapeutic agents, laxative abuse, 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 program in both diet and exercise. For weight loss caused by oral or dental problems, see the dentist. For weight loss caused by disease, follow prescribed therapy in treating the underlying cause.

You should 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 it cannot be unexplained
• 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?
• Is there fainting ?
• Do you have occasional uncontrollable hunger with palpitations , tremor , and sweating ?
• Has there been 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 drinking?
• 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 to prevent edema , poor healing, and muscle wasting .

It may be necessary to see a dietitian for nutritional counseling.