Chagas disease can cause a sudden, brief illness. This type of illness is known as acute. Or it can become a long-lasting, chronic condition. Both stages can be free of symptoms. Or there can be life-threatening symptoms in either phase.

Acute phase

The acute phase of Chagas disease lasts for weeks or months. It often has no symptoms. If there are symptoms, they're mostly mild. They may include:

• Swelling at the infection site.
• Fever.
• Tiredness.
• Rash.
• Body aches.
• Eyelid swelling.
• Headache.
• Loss of appetite.
• Nausea, diarrhea or vomiting.
• Swollen glands.
• A larger liver or spleen.

Symptoms that come on during the acute phase most often go away on their own. But if the infection isn't treated, Chagas disease stays in the body. Sometimes it moves to the chronic phase.

Chronic phase

Symptoms of the chronic phase of Chagas disease may appear 10 to 20 years after the infection starts. Or there might be no symptoms. In severe cases, Chagas disease symptoms may include:

• Irregular heartbeat.
• Heart failure.
• Sudden cardiac arrest.
• Trouble swallowing.
• Stomach pain or trouble passing stool, called constipation.

See your healthcare professional if you have been in an area where Chagas disease is widespread and you have symptoms of the condition.

The cause of Chagas disease is the parasite Trypanosoma cruzi. The parasite spreads from an insect known as the triatomine bug, also called the "kissing bug." The parasite can infect these insects when they swallow blood from an animal that is infected with the parasite.

Triatomine bugs live mainly in mud, thatch or adobe huts in Mexico, South America and Central America. They hide in crevices in the walls or roof during the day and come out at night. The bugs often feed on people while they sleep.

Infected bugs poop, called defecate, after feeding. The stool leaves parasites on the skin. The parasites can then enter the body through the eyes, mouth, a cut or scratch, or the wound from the bug's bite.

Scratching or rubbing the bite site, which often happens during sleep, helps the parasites enter the body. Once in the body, the parasites multiply and spread.

Chagas disease doesn't spread from being near an infected person. But the infection can come from:

• Eating uncooked food that has feces from bugs infected with the parasite.
• Being born to a person who is infected with the parasite.
• Getting donor blood or an organ from someone who was infected with the parasite.
• Being exposed to the parasite while working in a lab.
• Spending time in an area where there are infected wild animals, such as raccoons and opossums.

The following can increase the risk of getting Chagas disease:

• Living in rural areas of Central America, South America and Mexico.
• Living in a building that has triatomine bugs.
• Getting blood or an organ from a donor who has the infection.

It's rare for travelers to the at-risk areas in South America, Central America and Mexico to catch Chagas disease. That's because travelers tend to stay in buildings, such as hotels, that are less likely to have Triatomine bugs. Triatomine bugs are most often found in places made from mud, adobe or thatch. But travelers should not eat salads, uncooked vegetables and unpeeled fruits.

If Chagas disease moves to the long-lasting, called chronic, phase, there can be serious heart or digestive complications. These may include:

• Heart failure. Heart failure happens when the heart becomes so weak or stiff that it can't pump enough blood to meet the body's needs.
• Enlarged tube through which food travels from the mouth to the stomach, called the esophagus. This rare condition called megaesophagus is caused by the widening, called dilation, of the esophagus. This can cause trouble with swallowing and digestion.
• Enlarged colon. This condition called megacolon is caused by widening of the colon. Megacolon causes stomach pain, swelling and trouble with passing stool, called constipation.

If you live in a high-risk area for Chagas disease, these steps can help prevent infection:

• Don't sleep in a mud, thatch or adobe house. These types of homes are more likely to harbor triatomine bugs than are other types of buildings.
• Use netting soaked with bug killer, called insecticide, over the bed with sides tucked in.
• Use bug killers to remove insects from a home.
• Use insect repellent on exposed skin.

Your healthcare professional does a physical exam, asking about your symptoms and anything that put you at risk of Chagas disease. If you have symptoms of Chagas disease, two or more blood tests can confirm the diagnosis.

If you're diagnosed with Chagas disease, you're likely to have more tests. These tests can show whether the disease has become chronic and caused heart or digestive complications. Tests may include:

• Electrocardiogram. This records the heart's electrical activity.
• Chest X-ray. This imaging test can show an enlarged heart.
• Echocardiogram. This test uses sound waves to capture moving images of the heart. The images can show changes to the heart or how it works.
• Abdominal X-ray. This imaging test shows the stomach, intestines and colon.
• Upper endoscopy. A thin, lighted tube called an endoscope goes into the throat to show images of the esophagus.

Treatment for Chagas disease is to kill the parasite and ease symptoms.

During the acute phase of Chagas disease, the medicines benznidazole and nifurtimox (Lampit) may help. Both medicines are offered in the regions most affected by Chagas disease. In the United States, the medicines are approved for treatment of children younger than 18 with chronic infection.

Once Chagas disease becomes chronic, medicines won't cure the disease. But the medicines may be offered to help slow the disease and its most serious complications.

Other treatment depends on the symptoms.

• Heart-related complications. Treatment may include medicines, a pacemaker or other devices to control heart rhythm. Surgery, or even a heart transplant, might be needed.
• Digestive complications. Treatment may include diet changes, medicines and corticosteroids. In severe cases, surgery might be needed.

You are likely to start by seeing your main healthcare provider. You may then be sent to an infectious disease specialist.

Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

• Your symptoms and when they began.
• Key personal information, including travel to other countries, major stresses or recent life changes.
• All medicines, vitamins and supplements you take, including doses.
• Questions to ask your healthcare professional.

For Chagas disease, some basic questions to ask include:

• What's the most likely cause of my symptoms?
• What tests do I need?
• Is my condition likely to go away or to last?
• What treatments are there?
• I have these other health conditions. How can I best manage these conditions together?
• Can I pass this condition to others? Are those who traveled with me likely infected?
• Are there brochures or other printed material I can have? What websites do you suggest?

What to expect from your doctor

Your healthcare professional is likely to ask questions, including:

• Do your symptoms come and go or are they always with you?
• How severe are your symptoms?
• Does anything make your symptoms better?
• What, if anything, makes your symptoms worse? Have you lived or traveled anywhere, such as Mexico, where the triatomine bug or Chagas disease is common?