Loss of appetite Alternative Names
anorexia, decreased appetite
Most people have experienced a temporary loss of appetite at some time. This is rarely a worrisome symptom unless it lasts for more than a day or two.
What is going on in the body?
A loss of appetite can be quite concerning when it fails to go away. It can be a sign of a serious underlying condition, such as depression or cancer. It also commonly occurs during a sudden illness, such as an infection. When a loss of appetite continues for a long time, a person is at risk for malnutrition.
What are the signs and symptoms of the condition?
The doctor will need more information when a person mentions losing his or her appetite. For instance, he or she may ask:
What are the causes and risks of the condition?
- when the loss of appetite started
- whether the change in appetite was gradual or sudden
- whether the person feels sick or not
- whether the person feels nauseated or has vomited
- whether any weight loss has occurred
- whether the change in appetite is constant, or comes and goes
- what medications or drugs a person takes, if any
- what other medical conditions a person has, if any
- whether the loss of appetite is for all food, or just certain foods
- how the person's mood has been
- how food tastes when it is eaten
- whether or not the person has had any fever, diarrhoea, or headaches
There are many causes of a loss of appetite that continues for more than a few days, including:
Many other causes are also possible. Sometimes, no cause can be found.
- infections, such as pneumonia, hepatitis, HIV, influenza, or a kidney infection called pyelonephritis
- serious liver, kidney or heart disease. For instance, chronic renal failure, cirrhosis, or congestive heart failure can cause a loss of appetite.
- cancer of any kind, such as bowel cancer, stomach cancer, or a blood cancer called leukaemia
- blockage in the bowels, known as intestinal obstruction
- inflammation in the bowels or gut, such as occurs with pancreatitis, an inflammation in the pancreas, irritable bowel syndrome, or appendicitis
- endocrine problems, such as diabetes mellitus, or a condition that causes low thyroid hormone levels called hypothyroidism
- autoimmune disorders, conditions in which a person's immune system attacks his or her own body. Examples include rheumatoid arthritis and scleroderma.
- psychiatric conditions, such as depression, schizophrenia, or an eating disorder called anorexia nervosa
- medications or drugs, such as alcohol, narcotics, antibiotics, chemotherapy medications used to treat cancer, and a diabetes medication called metformin
- dementia, such as Alzheimer's disease, a condition that causes decreased memory and a decline in other brain functions
What can be done to prevent the condition?
Prevention is related to the cause. For instance, avoiding drugs known to cause a loss of appetite can prevent cases due to drugs. Proper control of diabetes can prevent cases due to this cause. Many cases cannot be prevented.
How is the condition diagnosed?
Diagnosis starts with a history and physical examination. This may be all that is needed to make the diagnosis. In other cases, further tests will be needed.
The specific tests ordered depend on the suspected cause. For instance, blood tests can help diagnose diabetes, hormone imbalances, and liver disease. Urine tests can help diagnose kidney infections or pregnancy. X-ray tests, such as a chest x-ray to look for pneumonia or lung cancer, may be needed in some cases. Other tests are also possible in certain cases.
What are the long-term effects of the condition?
Malnutrition, which is a lack of necessary food and nutrients in the body, is a concern if a loss of appetite lasts for more than a few weeks. Other long-term effects are related to the cause. For instance, diabetes can cause damage to many different organs in the body, including the kidneys, eyes, and nerves. Cancer can cause death. Infections that can be treated with antibiotics often go away and have no long-term effects.
What are the risks to others?
A loss of appetite is not contagious and poses no risk to others. However, the cause of a loss of appetite, such as an infection like pneumonia, may be contagious.
What are the treatments for the condition?
There are medications available to try to stimulate appetite in people with an incurable cause for their loss of appetite. If nausea is the main reason for the loss of appetite, medications to treat nausea, such as ondansetron or promethazine, can be given. For other people, nutrition supplements may be needed, such as high-kilojoule nutrition shakes or even artificial feeding through a gastrostomy tube. These measures are sometimes needed in people with dementia.
Other treatment is directed at the underlying cause. For instance, people with appendicitis usually need surgery. Those with infections often need antibiotics. Those with low thyroid hormone levels need hormone replacement pills. Those with cancer may need surgery, chemotherapy, or radiation therapy.
What are the side effects of the treatments?
Side effects depend on the treatments used. For instance, medications used to treat nausea may cause drowsiness. Antibiotics may cause allergic reactions or stomach upset. Surgery carries a risk of infection and bleeding.
What happens after treatment for the condition?
This depends on the cause. For instance, pregnant women often get their appetite back after several weeks and need no further treatment. Those with diabetes need lifelong monitoring and treatment. Those with cancer may die if treatment doesn't cure the cancer.
How is the condition monitored?
The person's weight and nutritional status may be monitored. Affected people can report any change in appetite or response from treatment to the doctor. Further monitoring is related to the underlying condition. For instance, those with low thyroid hormone levels who are taking hormone replacement pills may need thyroid function tests in the future to make sure the right dose is being given.
Author: Adam Brochert, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request