This fungal lung infection is caused by inhaling certain mold spores. It may be serious in those with asthma or other ongoing lung diseases.
Update Date: 22.09.2025
Aspergillosis is an infection caused by a mold called aspergillus. Aspergillus mold is a type of fungus. The illnesses resulting from aspergillosis infection usually affect the respiratory system. However, the illnesses can have very different symptoms, and some are more serious than others.
Aspergillus can be found indoors and outdoors. Most strains of this mold are harmless. However, a few strains can cause serious illnesses when certain people inhale the fungal spores. These strains are most dangerous for people with weakened immune systems, underlying lung disease or asthma.
In some people, the spores trigger an allergic reaction. Other people develop mild to serious lung infections. The most serious form of aspergillosis is called invasive aspergillosis. This occurs when the infection spreads to blood vessels and beyond.
Depending on the type of aspergillosis, treatment may involve observation, antifungal medicines or, in rare cases, surgery.
The symptoms of aspergillosis depend on the type of illness you develop:
Some people with asthma or cystic fibrosis have an allergic reaction to aspergillus mold. This allergic reaction is called bronchopulmonary aspergillosis. Symptoms of this condition include:
Certain ongoing lung conditions can cause air spaces to form in the lungs, called cavities. These conditions may include emphysema, tuberculosis or advanced sarcoidosis. When people with lung cavities also are infected with aspergillus, fungus fibers may find their way into the cavities. These fibers can grow into tangled masses known as fungus balls or aspergillomas.
Aspergillomas may produce no symptoms or cause only a mild cough at first. Over time and without treatment, however, aspergillomas can worsen the underlying lung condition and possibly cause:
Invasive aspergillosis is the most severe form of aspergillosis. It occurs when the infection spreads rapidly from the lungs to the brain, heart, kidneys or skin. Invasive aspergillosis occurs only in people whose immune systems are weakened. The immune system may be weakened because of cancer chemotherapy, bone marrow transplantation or a disease of the immune system. Untreated, this form of aspergillosis may be fatal.
Symptoms depend on which organs are affected. In general, invasive aspergillosis can cause:
Aspergillus can invade areas of your body other than your lungs, such as your sinuses. In your sinuses, the fungus can cause a stuffy nose and drainage that may contain blood. Fever, facial pain and headache also may occur.
If you have asthma or cystic fibrosis, see your healthcare professional whenever you notice a change in your breathing. Although aspergillosis may not be the cause, it's important to have breathing problems checked out.
Get immediate medical care if you have a weakened immune system and develop an unexplained fever, shortness of breath or a cough that brings up blood. In the case of invasive aspergillosis, it is important to get treated right away. In some cases, treatment with antifungal medicine begins as soon as aspergillosis is suspected, even before testing has confirmed the diagnosis.
Aspergillus mold is unavoidable. Outdoors, it's found in soil, decaying leaves and compost. It's also found on plants, trees and grain crops.
Everyday exposure to aspergillus is rarely a problem for people with healthy immune systems. When mold spores are inhaled, immune system cells surround and destroy them. But people who have a weakened immune system have fewer infection-fighting cells. This allows aspergillus to take hold, invading the lungs and, in the most serious cases, other parts of the body.
Aspergillosis is not contagious from person to person.
Your risk of developing aspergillosis depends on your overall health and the extent of your exposure to mold. In general, these factors make you more vulnerable to infection:
Depending on the type of infection, aspergillosis can cause a variety of serious complications:
It's nearly impossible to avoid exposure to aspergillus. If you have had a transplant or are undergoing chemotherapy, try to stay away from places where you're likely to encounter mold. Places may include construction sites, compost piles and buildings that store grain. If you have a weakened immune system, your healthcare professional may advise you to wear a face mask to avoid being exposed to aspergillus and other airborne infectious agents.
Diagnosing an aspergilloma or invasive aspergillosis can be difficult. Aspergillus is common in all environments. However, it is difficult to tell it apart from certain other molds under the microscope. The symptoms of aspergillosis also are similar to those of other lung conditions such as tuberculosis.
Your healthcare professional is likely to use one or more of the following tests to pinpoint the cause of your symptoms:
Aspergillosis treatments vary with the type of disease. Possible treatments include:
All antifungal medicines can have serious side effects. These may include kidney and liver damage. Interactions between antifungal medicines and other medicines also are common.
Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.
People who develop aspergillosis usually have an underlying condition. Conditions may include asthma, cystic fibrosis, or a weakened immune system due to illness or to immune-suppressing medicines. If you have symptoms of aspergillosis and are already being treated for a medical condition, call the healthcare professional who provides your care for that condition. In some cases, when you call to set up an appointment, your health professional may recommend urgent medical care.
Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.
Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For aspergillosis, some basic questions to ask include:
Don't hesitate to ask other questions.
Be prepared to answer questions, such as:
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