Loss of Appetite

Overview, Causes, & Risk Factors

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 causes and risks of the condition?

There are many causes of a loss of appetite that continues for more than a few days, including:

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 colon cancer, stomach cancer, or a blood cancer called leukemia

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

pregnancy

dementia, such as Alzheimer's disease, a condition that causes decreased memory and a decline in other brain functions

Many other causes are also possible. Sometimes, no cause can be found.

Symptoms & Signs

What are the signs and symptoms of the condition?

The healthcare provider will need more information when a person mentions losing his or her appetite. For instance, he or she may ask:

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, diarrhea, or headaches

Diagnosis & Tests

How is the condition diagnosed?

Diagnosis starts with a history and physical exam. 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.

Prevention & Expectations

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.

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.

Treatment & Monitoring

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. These medications include megestrol and dronabinol. 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-calorie 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 healthcare provider. 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.