Laura 's first symptoms were a fever, chills, rash and constant fatigue. Her symptoms worsened as she developed muscle aches, a headache, night sweats, an increased heart rate and a dry cough that wouldn't go away. She knew it was time to see her healthcare provider when she started having trouble breathing.
She thought it might be COVID-19, but the test came back negative. Laura's doctor ordered other tests, including a chest X-ray, which showed she had pneumonia. She was prescribed antibiotics, medications designed to kill bacteria, the most common cause of pneumonia. But after completing the antibiotics, Laura’s symptoms did not improve. She returned to the doctor’s office two more times, each time after completing an additional course of antibiotics with no improvement in her symptoms. Finally, after another negative COVID-19 test, she asked her doctor to test her for a fungal disease called Valley fever (coccidioidomycosis). The test came back positive.
You may not typically think of pneumonia as a lung infection caused by a fungus. However, like Laura experienced, pneumonia can be caused by fungi. Usually, people with Valley fever get better on their own, but sometimes medication is needed. Treatment for Valley fever, and other fungal pneumonias, requires antifungal drugs. Antibiotics, which treat bacterial infections, will be ineffective.
Coccidioidomycosis (Valley fever), histoplasmosis, and blastomycosis are three types of fungal pneumonias caused by fungi that live in different parts of the United States. Fungal pneumonias are often misdiagnosed, delaying treatment when needed. Delayed treatment can cause more severe infections, sometimes leading to long-term health conditions or death.
What Is Valley Fever (Coccidioidomycosis)?
Valley fever is a lung infection caused by Coccidioides, a fungus that lives in the soil. The fungus lives primarily in the southwestern United States, Pacific Northwest, parts of Mexico, Central America and South America. You can get Valley fever by breathing in the spores from Coccidioides, though not everyone who does so will get sick.
Valley fever causes typical lung infection symptoms, like cough, fever, chills and difficulty breathing. Pneumonia can affect anyone, but it is more serious for young children, older adults, and people with weakened immune systems.
Many people can get better on their own without any treatment. However, sometimes Valley fever can cause severe lung infections or in rare cases, the infection can spread to other parts of the body. In these situations, antifungal treatment is needed to reduce symptoms or stop them from getting worse.
What Is Histoplasmosis?
Histoplasmosis is a lung infection caused by breathing in Histoplasma capsulatum, a fungus that lives in soil contaminated by bird or bat droppings. Histoplasma is most commonly found in the states surrounding the Ohio and Mississippi river valleys covering a large area of the Midwest. It has also been found in parts of Central and South America, Africa, Asia and Australia.
Most of the time, when people breathe in the fungal spores, they do not get sick. However, histoplasmosis can cause mild to life-threatening pneumonia symptoms that appear between 3 and 17 days after exposure to the fungus. These symptoms include fever, chills, headache, muscle aches, fatigue, cough and chest discomfort. Histoplasmosis can develop into a long-term lung infection, specifically if you have a weakened immune system. In rare cases, it can spread beyond the lungs to other parts of your body, including the brain and spinal cord (meningitis).
Sometimes, symptoms go away on their own without treatment. Antifungal medication prescribed by a doctor may be needed to treat severe or chronic (long-term) lung infections or infections that spread to other parts of the body. Treatment can range from three months to a year. The length of treatment depends on the severity of the infection and the patient's immune status.
What Is Blastomycosis?
Blastomycosis is a lung infection caused by breathing in Blastomyces spores. Blastomyces live in moist soil that consists of rotting plants, leaves or wood. If infected soil or plants are disturbed, they release tiny spores into the air which, if inhaled, can cause a lung infection in approximately 50% of people. If left untreated, sometimes the infection spreads to other parts of the body.
Infections typically cause pneumonia symptoms, including fever, cough, shortness of breath, weight loss, body aches, chest pain, fatigue and night sweats. If the infection spreads beyond the lungs you may also develop a rash, blisters or ulcers on your skin. In severe cases, blastomycosis may also spread to the bones, joints, brain and spinal cord. People with weakened immune systems are at risk of severe illness. If you have blastomycosis symptoms, you will likely need to take antifungal treatment for six months to one year. The length of treatment depends on a person’s immune system and the severity of the infection.
When to Ask Your Doctor About Testing for Fungus
Valley fever, histoplasmosis, and blastomycosis may have similar symptoms of bacterial and viral pneumonia. Because pneumonia caused by bacteria is more common than pneumonia caused by fungi, healthcare providers usually prescribe antibiotic treatment first. But antibiotics will not help treat Valley fever, histoplasmosis, or blastomycosis, so if symptoms do not improve or worsen, you should talk to your healthcare provider about testing for fungal pneumonia.
Learn more at Lung.org/pneumonia.
Blog last updated: September 22, 2025
