Edit Article

How to Know if You Have Chagas Disease

Three Methods:Recognizing Early SymptomsRecognizing Late SymptomsKnowing the Risk FactorsCommunity Q&A

Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi. The disease is common in central and South America and is transmitted to humans by the Triatomine (reduviid) bug. If you have recently traveled in areas where chagas is prevalent, scroll down to Step 1 to learn more about its symptoms and who may be at risk.

Recognizing Early Symptoms

The early stage, which is also known as the acute phase, starts approximately one week after the bite occurs.

  1. 1
    Look for swelling at the bite site. The swelling usually appears one week after the bite. The bite site becomes a boil-like, hard and violet colored lesion that may persist for several weeks. The swelling is due to multiplication of the parasite locally in the tissue that leads to inflammation. It is known as “Chagoma”.[1]
    • A chaga bite may be confused with other types of insect bites. However, the swelling of a bee sting or ant bite develops quickly and is extremely itchy while the swelling of a reduviid bug bite is less itchy.
  2. 2
    Watch out for swelling of the eyelids. If the parasite infects the conjunctiva there may be painless, non-itchy swelling of the eyelids. Your eyelids will then appear firm and reddish. They may also take on a purple hue. This symptom is known as Romana’s sign. There may also be swelling of the surrounding area if the infection spreads locally.[2]
    • This is a very reliable sign of Chagas disease. While other diseases can cause your eyelids to swell, chaga is the only one that results in painless, non-itchy swelling. Lid swelling due to bacterial or viral viral infections will be painful and itchy accompanied by watering. A stye caused by a bacterial infection causes development of boil like swelling in a single lid.
  3. 3
    Keep track of any fever you experience. Your fever will most likely be non-specific and low grade. It may also appear as a fever that lasts for a few hours a day and then disappears for the rest of the day and night.
  4. 4
    Pay attention to any sudden rashes. Chagas may cause a transient, non-itchy skin rash that resembles the rash you get when you have measles. Luckily, it is usually self limiting and resolves within a few days.
  5. 5
    Check to see if your lymph nodes are swollen. Lymph nodes close to the site of infection might become swollen after the bite. The parasites will travel along lymph vessels to reach those lymph nodes where they induce inflammation. Swelling of the lymph nodes means they are responding and trying to kill or eliminate the invading organisms.
    • Lymph nodes fight against infection and are found in different parts of the body. In normal individuals, the lymph nodes cannot be felt or palpated. They are located beneath the skin of armpit, angle of mouth or neck.
  6. 6
    Note any digestive problems you experience. There may be loss of appetite, feeling of nausea, or the development of vomiting or diarrhea. However, these digestive problems are non-specific and result from many different health issues, so they are not the best measurements when trying to determine if you have chagas or not.
  7. 7
    Monitor fatigue and body aches. These are also non-specific symptoms. Fatigue may develop because of the acute stress the infection is putting on your body. When the body recognizes an infection, it fights against the invading organisms, which in turn causes you to feel tired. A feeling of pain at different sites in the body is generally due to the toxic substances that are produced at the site of the infection and inflammation.

Recognizing Late Symptoms

The late symptoms, or chronic phase, begins about two months from the start of or the initial infection up to ten years to twenty years thereafter. It is made up of the indeterminate phase, cardiac issues, and gastrointestinal problems.

  1. 1
    Understand the indeterminate phase. This is seen in 60% to 70% of the patients in the chronic phase. These patients do not have heart, gastrointestinal (esophagus or colon), and neurological (brain or nerves) symptoms of Chagas disease. Nevertheless, around 2% to 5% of these patients later have heart, esophagus and/or large intestinal or colonic symptoms. This form occurs eight weeks to ten weeks after the start of infection and is asymptomatic phase, which means it is without symptoms or signs of illness.
  2. 2
    Watch out for heart problems. Heart issues caused by chagas are referred to as Chagas Cardiac disease. If left untreated, the parasites gradually damage the heart. Heart muscles are destroyed with fibrous tissue formation. Heart chambers are dilated and muscles cannot contract rhythmically and efficiently, which may lead to heart failure.[3]
    • If you feel irregular heart beat or missed beat, it may be an early sign of heart malfunction.
    • If heart failure develops, there will be accumulation of fluid in the lungs. You will experience breathlessness, fatigue and nocturnal cough with frothy sputum.
  3. 3
    Monitor digestive problems. Long standing infection may damage nerves in your digestive tract. The esophagus (gullet) and colon are most commonly affected. They become dilated as there is loss of peristalsis, or the contraction of the intestine to propel food bolus from the mouth to the anus. You will either have issues with your esophagus or your colon.[4]
  4. 4
    Look for signs of megaesophagus. Megaesophagus is defined as the dilatation or enlargement of the esophagus. Symptoms of megaesophagus are difficulty in and painful swallowing to solid and/or liquid foods, difficulty of breathing, regurgitation, weight loss, and food aspiration. Due to this condition, previously-eaten food may go back towards the mouth and may pass through the windpipe and cause cough and pneumonia.
  5. 5
    Go to the hospital if you see signs of megacolon. Megacolon is defined as the dilatation or enlargement of the large intestine or the colon.Megacolon presents as constipation, impacted feces, or twisting of the large intestine. Symptoms of colonic infarction would be pain on the whole abdomen, passage of watery to loose stools (diarrhea), fever, and vomiting. Both colonic infarction and obstruction are emergencies requiring surgery.

Knowing the Risk Factors

  1. 1
    Know that the Triatomine (reduviid) bug is the main cause of chagas. The bug acquires the infection while sucking the blood of an infected animal. The parasite then multiplies within the intestine of the bug and is excreted in its feces. The parasite enters you through the wound created when the bug bites you.[5]
    • Triatomine(reduviid) bugs usually come out at night for feeding when people tend to sleep. Their favorite site to bite is the face (which is why they are called “kissing bugs”).
    • The parasite can also enter the human body through the intact mucus membrane of the mouth or lips if the bug deposits excreta near the lips. Conjunctiva of the eye may be infected while rubbing the excreta against the eye.
  2. 2
    Know where this disease is most prevalent. The kissing bug is found in parts of Central and South America. It generally lives in the walls and cracks of substandard houses, or out in the woods. The countries where it has been found include[6]:
    • Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, French Guiana, Suriname, Guyana and Venezuela.
  3. 3
    Understand that you can get it through bad blood transfusion. Sometimes, chagas disease does not have any symptoms that go along with it. If a person is asymptomatic, meaning they don’t have symptoms, and they donate blood, they might give someone else the disease.[7]
    • The same goes for organ donation if the donor is infected.
  4. 4
    Know that an infected mother may also have an infected baby, The parasite can cross the placenta and infect the baby in the mother’s womb. In that case, the baby may be born with problems like abdominal swelling, jaundice, or lungs or heart defects.

Community Q&A

Add New Question
  • What lab test do I ask for?
    Mandolin S. Ziadie, M.D.
    Your doctor should order Trypanasoma cruzi serologic tests to evaluate you for the disease. Tests for Chagas disease use antibodies against the organism that causes it, which is called Trypanasoma cruzi. The parasite can also be seen by smearing blood samples on a glass slide but this is much harder and can sometimes appear negative even in patients that have the disease. Serologic tests are much better.
  • What do the bite marks look like?
    Mandolin S. Ziadie, M.D.
    The bites start out small and subtle, but they become larger, red, swollen, and hard. The marks can grow to the size of a dime or quarter.
Unanswered Questions
Show more unanswered questions
Ask a Question
200 characters left


  • If you are traveling to an area that is known to have chagas-carrying bugs, invest in a large amount of bug repellant and take precautions to make sure that your skin is covered when you sleep.


  • If you have any of the symptoms listed above, see your doctor immediately.

Article Info

Categories: Infectious Diseases

In other languages:

Español: saber si tienes la enfermedad de Chagas, Português: Descobrir se Você Tem Doença de Chagas


Did this article help you?