Aspergillosis is a group of illnesses caused by a common mould called Aspergillus. We breathe in its microscopic spores every day, usually without harm. Most people never become ill because healthy lungs and the immune system clear the spores from the airways.
In some people, particularly those with asthma, existing lung disease or a weakened immune system, Aspergillus can cause an allergic reaction, persistent airway problems or infection. The type of aspergillosis, its symptoms and its treatment can therefore be very different from one person to another.
This page explains what aspergillosis is and helps you find information about diagnosis, treatment and living with the condition.
Patient-centred information from the National Aspergillosis Centre. This guide combines specialist clinical knowledge with the questions, experiences and practical concerns raised by people living with aspergillosis and their carers.
Key points
- Aspergillosis is caused by the mould Aspergillus.
- Aspergillus spores are common in the air, and most people breathe them in every day without becoming ill.
- Aspergillosis is not one single disease: it is a group of different conditions.
- Some forms are mainly allergic conditions; others are infections.
- The type of illness depends on your lungs, immune system and how your body reacts to the fungus.
New to aspergillosis?
If you have recently been diagnosed, or your doctor suspects aspergillosis, these links may help you get started:
- Which type of aspergillosis do I have?
- How doctors diagnose aspergillosis
- Treatment and management
- Living with aspergillosis
- Patient support meetings
Where does Aspergillus come from?
Aspergillus is a mould that grows naturally in the environment. It may be found in soil, compost, decaying leaves, dust and damp indoor areas. Because it is so common, its spores are often present in the air around us.
Most of the time this is not a problem. Healthy lungs and a healthy immune system usually remove the spores without difficulty. Problems can arise when the lungs are already damaged, the airways are sensitive, or the immune system is weakened or altered.
Aspergillosis is a group of conditions
The word aspergillosis is an umbrella term for several related conditions caused by Aspergillus. The important difference is the way the body reacts to the fungus. Different forms need different tests, treatments and follow-up.
Allergic Aspergillus conditions
In some people, especially those with asthma or related airway disease, the immune system overreacts to Aspergillus. The fungus may not be invading tissue, but it can still trigger substantial inflammation and symptoms.
Chronic Aspergillus infections
In other people, particularly those with pre-existing lung damage, Aspergillus can persist in the lungs and cause long-term infection or inflammation.
- Chronic pulmonary aspergillosis (CPA)
- Aspergillus bronchitis
- Aspergillus nodules
- Aspergilloma (fungal ball)
Invasive and Acute Aspergillus Infections
Rarely, Aspergillus can cause a more acute or invasive infection. This mainly affects people who are severely unwell or whose immune systems are substantially weakened by illness or medical treatment.
Invasive infection is very different from chronic forms such as CPA, ABPA, Aspergillus bronchitis or an aspergilloma. Having one of these long-term conditions does not mean that infection will spread through the body.
Aspergillus can also occasionally cause local infections of the ear, eye or nails. These are usually separate, local problems rather than a sign that lung aspergillosis is spreading.
Who is most at risk?
Most people breathe in Aspergillus spores without becoming ill. Risk increases when the lungs are already vulnerable or the immune system cannot respond in the usual way.
People who may be at higher risk include:
- people with asthma, bronchiectasis or chronic obstructive pulmonary disease (COPD)
- people who have had tuberculosis or other lung damage
- people with cystic fibrosis
- people taking medicines that suppress the immune system
- people whose immune systems are weakened by illness or medical treatment
What symptoms can aspergillosis cause?
Symptoms vary depending on the type of aspergillosis, but may include:
- persistent cough, wheezing or breathlessness
- bringing up sputum or mucus plugs
- chest discomfort or pain
- fatigue or weight loss
- coughing up blood in some cases
These symptoms overlap with many other lung conditions, which is one reason aspergillosis can take time to diagnose.
Read more about symptoms of aspergillosis →
Why can aspergillosis be difficult to diagnose?
Aspergillosis can be difficult to recognise because it is a group of conditions rather than one disease, and its symptoms often overlap with asthma, bronchiectasis, chronic lung infection and other respiratory illnesses.
Doctors may use a combination of evidence, including symptoms, scans, blood tests, sputum results and medical history. One test alone is often not enough.
How is aspergillosis treated?
Treatment depends on the type of aspergillosis and the individual. Some people need antifungal medicines. Others may need steroids, biologic drugs, airway clearance, monitoring or a combination of treatments. Some conditions need long-term management rather than a short course of treatment.
Read more about treatment and management →
Living with aspergillosis
Living with aspergillosis often involves more than treating the fungus itself. Many people also need help with fatigue, breathlessness, exercise, nutrition, anxiety, practical adjustments and understanding how to reduce harmful exposures.
Support from other patients, carers and specialist teams can make a real difference.
Common questions
Is aspergillosis contagious?
No. Aspergillosis is not usually passed from one person to another.
Does everyone who breathes in Aspergillus get ill?
No. Most people breathe in spores regularly without becoming ill.
Is aspergillosis one disease?
No. It is a group of different conditions caused by Aspergillus.
Can aspergillosis be cured?
That depends on the type. Some forms can be treated effectively, while others need long-term monitoring and management.
Why have I never heard of it before?
Some forms of aspergillosis are uncommon, and many symptoms overlap with more familiar lung conditions. This can make diagnosis and awareness more difficult.
Where to go next
- Learn about the different types of aspergillosis
- Understand how doctors diagnose aspergillosis
- Explore treatment and management options
- Read about living with aspergillosis
- Search the Knowledge Hub for patient questions
Last reviewed: September 2026
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