Weight loss occurs when a person burns more calories, or energy, than he or she takes in. It may be deliberate or unintentional.
A loss of weight is due to one of three factors:
Weight loss may or may not be intended. Unplanned weight loss is often a sign of serious illness.
Some of the causes of weight loss are as follows:
Other causes of weight loss are also possible. Sometimes a cause cannot be found.
Those who lose weight through physical activity and eating a proper diet have little to worry about. If anything, the main symptom of this type of weight loss is that a person feels healthier.
Unintended weight loss is a cause for concern. In this setting, the healthcare provider will want to know more information, such as:
Diagnosis of the cause of weight loss starts with a medical history and a physical exam. This may be all that is needed to figure out the cause in some cases. In other cases, further tests are needed. Blood and urine tests may be ordered to diagnose underlying health problems.
X-ray tests may be done, such as a chest X-ray to look for heart or lung disease. A special X-ray test, called a CT scan, can look for cancer of the pancreas or liver.
For unintended weight loss, prevention is related to the cause. Avoiding the drugs that cause weight loss could prevent those cases due to drugs. Practicing safer sex could prevent many cases due to HIV infection. Many cases of unintended weight loss cannot be prevented.
Intentional weight loss from a healthy diet and exercise decreases the risk of:
The long-term effects of unintentional weight loss are related to the cause. Cancer, diabetes, HIV, and severe heart, liver, or kidney disease are common causes of death. Many people who abuse drugs have long-term effects related to social, legal, and psychological problems from the drug abuse.
Weight loss is not contagious. If infection is the cause of unintended weight loss, however, the infection may be contagious. HIV, for example, can be sexually transmitted. Tuberculosis can be spread through respiratory secretions.
Weight management plans are helpful for obese or overweight people who want to lose weight.
Treatment for unintended weight loss is directed at the cause. For example, a person with diabetes may need insulin injections or other medicines to control his or her blood glucose levels. Someone who is abusing drugs may need to enter a rehabilitation program. An individual with an infection may need antibiotics. A person with cancer may need surgery, chemotherapy, or radiation therapy.
Side effects depend on the treatment used for weight loss. Medicines may cause allergic reactions or stomach upset. Surgery carries a risk of bleeding, infection, and allergic reactions to anesthesia.
A person who loses weight from diet and exercise often feels healthier and happier. Someone with unintentional weight loss may be cured by treatment, such a person with depression. Others may die, such as those with advanced cancer, HIV, or severe liver disease.
Weight can be monitored at home and at every visit to the healthcare provider. Further monitoring is related to the cause. For example, a person with diabetes needs frequent blood tests to monitor his or her blood glucose level. Any new or worsening symptoms should be reported to the healthcare provider.
Author:Adam Brochert, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:07/31/01
Reviewer:Gail Hendrickson, RN, BS
Date Reviewed:07/12/01
Harrison's Principles of Internal Medicine, 1998, Fauci et al.