Hot tub lung illustration

What is Hot Tub Lung? – Explained (2024)

by | Updated: Apr 18, 2024

Hot tub lung is an intriguing, yet lesser-known respiratory condition known scientifically as hypersensitivity pneumonitis.

The term may sound peculiar, but it points to a serious health risk associated with a seemingly benign recreational activity: hot tub usage.

Often presenting with symptoms similar to pneumonia, this little-known condition has been on the rise, posing health risks that range from uncomfortable to life-threatening.

This article will explain what hot tub lung is, provide an overview of its causes and prevention strategies, and offer a few tips on how to stay safe while using a hot tub.

What is Hot Tub Lung?

Hot tub lung is a type of hypersensitivity pneumonitis, a lung condition caused by inflammation resulting from the inhalation of certain substances, which, in this case, is primarily associated with hot tub use. It’s triggered by exposure to a type of bacteria known as Mycobacterium avium complex (MAC), which thrives in warm, wet environments.

When the hot tub is used, these bacteria can become aerosolized, and when they’re inhaled, they can cause an inflammatory response in the lungs.

Mycobacterium avium complex (MAC) Illustration Vector

Causes and Risk Factors

Hot tub lung is caused primarily by the inhalation of aerosolized Mycobacterium avium complex (MAC), a type of bacteria that thrives in warm, wet environments such as hot tubs.

When you use a hot tub, particularly when the jets are on, these bacteria can become aerosolized, or turned into tiny droplets that can be inhaled into the lungs.

Once in the lungs, these bacteria can trigger an immune response leading to inflammation and the symptoms of hot tub lung.

Certain factors can increase the risk of developing hot tub lung:

  • Frequent Hot Tub Use: The more often you use a hot tub, particularly if it’s not well-maintained, the greater your risk.
  • Indoor Hot Tubs: Indoor hot tubs might pose a greater risk because they often have less ventilation than outdoor hot tubs. This can allow bacteria-filled aerosols to build up in the air.
  • Poor Hot Tub Maintenance: Not cleaning your hot tub regularly or not keeping the water appropriately treated with disinfectants can allow MAC and other bacteria to multiply.
  • Immunosuppression: People with weakened immune systems might be more susceptible to hot tub lung, as their bodies may have a harder time fighting off the bacterial infection.
  • Genetic Factors: Some research suggests that certain genetic factors might make some people more prone to developing hypersensitivity pneumonitis, the category of lung disease to which hot tub lung belongs.

It’s important to note that not everyone who uses a hot tub will develop hot tub lung. Many people use hot tubs regularly without any issues.

However, understanding these causes and risk factors can help you take steps to minimize your risk and maintain your lung health.

Signs and Symptoms

Signs and symptoms of hot tub lung may resemble those of other respiratory conditions, making it somewhat difficult to diagnose.

he onset can be gradual, occurring over weeks to months, but sometimes it may present with acute symptoms. The key symptoms to look out for include:

  • Cough: A persistent and dry cough is a common symptom of hot tub lung. This is often the result of inflammation and irritation in the airways.
  • Shortness of Breath: Especially noticeable during physical activity, individuals may struggle with their breathing or feel like they can’t get enough air.
  • Fatigue: Generalized tiredness or a lack of energy is common in individuals with hot tub lung. This can be due to the body’s energy being redirected towards fighting inflammation and infection.
  • Fever: Some individuals may experience a low-grade fever, often accompanied by chills.
  • Night Sweats: Night sweats, where individuals sweat excessively during the night irrespective of the ambient temperature, may be a symptom.
  • Unintended Weight Loss: While less common, some individuals may experience weight loss that isn’t linked to changes in diet or exercise.
  • Chest Discomfort or Tightness: This can occur due to the inflammation and congestion in the lungs.

The onset of these symptoms can occur soon after exposure to contaminated water in a hot tub, and their severity may vary among different individuals.

Remember: These symptoms could also be indicative of other respiratory conditions, such as bronchitis, pneumonia, or tuberculosis. Therefore, if you are experiencing these symptoms, especially if you frequently use a hot tub, it’s important to consult a healthcare professional for an accurate diagnosis.

Radiographic Findings

Radiology plays a crucial role in the diagnosis and monitoring of hot tub lung. Chest radiographs and high-resolution computed tomography (HRCT) scans are commonly used imaging techniques.

Chest x-rays often show a pattern of diffuse micronodules (tiny nodules spread throughout the lung fields). These findings, while not exclusive to hot tub lung, can be an important clue for physicians, especially in individuals with a history of hot tub use.

However, the HRCT scan of the chest provides a more detailed view of the lungs, and the findings are often more specific.

A typical HRCT scan of hot tub lung shows diffuse, small (less than 5mm), poorly defined nodules throughout the lung fields, primarily in the middle and lower lung zones. In some cases, ground-glass opacities may also be seen.

These imaging findings reflect the inflammation and tiny granulomas (small areas of inflammation due to the immune response) caused by the Mycobacterium avium complex bacteria.

Of course, these radiologic findings alone cannot confirm a diagnosis of hot tub lung. They must be interpreted in conjunction with clinical history, physical examination, and other diagnostic tests such as sputum cultures and lung biopsies.

Treatment and Management

Treatment and management of hot tub lung revolve primarily around minimizing exposure to the causative bacteria and managing the symptoms. Some common strategies include:

  • Avoidance of Exposure: The first step in treating hot tub lung is to stop using the contaminated hot tub. This removes the source of exposure to the Mycobacterium avium complex bacteria, halting further progression of the disease.
  • Corticosteroid Therapy: For more severe cases, or when symptoms persist after stopping hot tub use, doctors may prescribe corticosteroids. These drugs help reduce inflammation in the lungs and ease symptoms.
  • Antimicrobial Therapy: If a bacterial infection is confirmed, treatment may include antimicrobial therapy targeting the Mycobacterium avium complex. This typically involves a regimen of multiple antibiotics taken over several months.
  • Oxygen Therapy: Oxygen therapy may be required for patients who have low oxygen levels in their blood due to the condition.
  • Pulmonary Rehabilitation: Pulmonary rehabilitation programs can be beneficial in managing hot tub lung. These programs often involve exercise training, nutritional advice, and education about the condition.
  • Avoidance of Respiratory Irritants: Patients should avoid exposure to other respiratory irritants, such as tobacco smoke, to prevent additional lung damage.

It’s important to note that the recovery period for hot tub lung can vary depending on the severity of the condition and the individual’s overall health.

Regular follow-up appointments are usually necessary to monitor the patient’s progress and adjust treatment as needed.

A multidisciplinary approach involving pulmonologists, infectious disease specialists, and other healthcare professionals often yields the best outcomes.

Complications and Prognosis

If hot tub lung is left untreated or misdiagnosed, it can lead to a variety of complications. Chronic inflammation and scarring (fibrosis) in the lungs can develop, potentially impairing lung function.

This can lead to a decrease in the lung’s ability to exchange oxygen and carbon dioxide, potentially causing respiratory failure in severe cases.

Additionally, the persistent inflammation can lead to pulmonary hypertension, a type of high blood pressure that affects the arteries in the lungs and the right side of the heart.

The prognosis of hot tub lung varies depending on the individual’s overall health, the severity of the condition, and the timeliness of treatment.

If detected early and managed appropriately – including removing exposure to the source and possibly medication intervention – the prognosis is generally good. Most people can recover completely with no lasting effects on lung function.

However, if the condition is severe or treatment is delayed, some degree of lung damage may persist even after treatment, leading to chronic respiratory issues.

Hence, it’s critical to seek medical attention if someone who frequently uses a hot tub develops persistent respiratory symptoms.

Person with hot tub lung sickness vector

How to Prevent Hot Tub Lung

Preventing hot tub lung is largely a matter of maintaining good hot tub hygiene and adhering to a regular maintenance routine. Here are some important steps to prevent this condition:

  • Regular Cleaning and Disinfecting: Clean your hot tub regularly and maintain a proper balance of disinfectants like chlorine or bromine. These chemicals help control the growth of bacteria, including Mycobacterium avium complex, which is responsible for hot tub lung.
  • Water Temperature: The water in your hot tub should not exceed recommended temperatures. High temperatures can degrade disinfectants and promote the growth of certain bacteria.
  • Regular Water Changes: Replace the water in your hot tub regularly. This helps remove any bacteria and other contaminants.
  • Proper Ventilation: If your hot tub is indoors, ensure the room is well-ventilated. Good ventilation helps disperse aerosols that might contain bacteria, reducing the concentration you might inhale.
  • Cover Your Hot Tub: When not in use, cover your hot tub to prevent debris and dirt from contaminating the water.
  • Filter Maintenance: Clean and replace the filters as recommended by the manufacturer. Filters can harbor bacteria if not cleaned and replaced regularly.
  • Professional Maintenance: Consider regular maintenance checks by a professional who can ensure the hot tub is functioning correctly and the water chemistry is balanced.
  • Monitoring Health: If you use a hot tub regularly and start to notice respiratory symptoms such as a persistent cough, fatigue, or difficulty breathing, it’s worth consulting a healthcare professional. Early detection of hot tub lung can make treatment more straightforward.

By taking these steps, you can reduce the risk of hot tub lung and enjoy the health benefits of soaking in hot water without compromising your respiratory health.

FAQs About Hot Tub Lung

Is Hot Tub Lung a Thing?

Yes, hot tub lung is indeed a thing. It’s a form of hypersensitivity pneumonitis, a condition characterized by lung inflammation due to inhalation of certain substances.

In this case, the condition is primarily associated with inhaling aerosolized Mycobacterium avium complex bacteria, which thrive in warm, wet environments such as hot tubs.

What Are the Symptoms of Hot Tub Lung?

The symptoms of hot tub lung can include persistent dry cough, shortness of breath (especially during physical activity), fatigue, low-grade fever, night sweats, unintended weight loss, and chest discomfort or tightness.

These symptoms can resemble those of other respiratory conditions, making hot tub lung somewhat challenging to diagnose.

How Long Does It Take for Hot Tub Lung to Go Away?

The recovery time for hot tub lung varies depending on several factors, including the severity of the condition, the individual’s overall health, and how quickly treatment was started after the onset of symptoms.

If the disease is mild and detected early, symptoms may resolve within weeks to a few months after cessation of hot tub use and appropriate treatment.

In more severe cases or when treatment is delayed, recovery might take longer, and some lung damage may be permanent.

How Do You Fix Hot Tub Lung?

The first step in treating hot tub lung is to stop using the contaminated hot tub to halt further exposure to the causative bacteria.

For more severe cases or where symptoms persist after stopping hot tub use, doctors may prescribe corticosteroids to reduce inflammation and ease symptoms. Antimicrobial therapy may also be required if a bacterial infection is confirmed.

Oxygen therapy and pulmonary rehabilitation programs can also be beneficial in managing the condition. Regular follow-ups with healthcare providers are necessary to monitor progress and adjust treatment as needed.

Does Hot Tub Lung Go Away on Its Own?

Hot tub lung may resolve on its own if the disease is mild and the individual stops using the contaminated hot tub, thereby removing exposure to the causative bacteria.

However, in more severe cases, or where symptoms persist after stopping hot tub use, medical treatment may be necessary.

Therefore, it’s recommended to consult a healthcare professional if persistent respiratory symptoms develop, especially for frequent hot tub users.

Can You Get a Lung Infection from a Hot Tub?

Yes, you can potentially get a lung infection from a hot tub. The condition known as hot tub lung is caused by inhaling aerosolized Mycobacterium avium complex bacteria that are often found in hot tubs, especially those not properly maintained.

These bacteria can cause an infection and inflammation in the lungs, leading to hot tub lung.

How to Avoid Hot Tub Lung?

Avoiding hot tub lung involves maintaining good hot tub hygiene and adhering to a regular maintenance routine.

This includes cleaning and disinfecting the hot tub regularly, maintaining a proper water temperature and balance of disinfectants, replacing the water regularly, ensuring good ventilation if the hot tub is indoors, covering the hot tub when not in use, and regularly cleaning and replacing the filters.

Regular maintenance checks by a professional can also help prevent hot tub lung. Lastly, if you develop persistent respiratory symptoms and you’re a frequent hot tub user, consult a healthcare professional promptly.

Final Thoughts

Hot tub lung, though an uncommon condition, represents an important intersection of recreational activities and respiratory health.

Originating from the seemingly innocuous act of enjoying a hot tub, the inhalation of aerosolized Mycobacterium avium complex bacteria can lead to a chain of inflammatory reactions in the lungs.

Awareness is crucial in navigating this health challenge; therefore, recognizing the symptoms, understanding the risks, and adopting preventive measures can play a significant role in maintaining lung health.

Proper hot tub maintenance and hygiene practices can allow us to continue enjoying these relaxing amenities without compromising our well-being.

As with many health issues, early detection and treatment of hot tub lung are vital for a positive outcome, highlighting the importance of prompt medical attention for persistent respiratory symptoms, particularly for frequent hot tub users.

In the end, hot tub lung serves as a reminder that even our leisure activities can have unexpected health implications, and staying informed is key to wellness.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


  • American Lung Association. Hypersensitivity Pneumonitis.
  • Yasin, Hassaan et al. “Hot Tub Lung: A Diagnostic Challenge.” Cureus vol. 9,8 e1617. 27 Aug. 2017
  • Hanak, Viktor, et al. “Hot Tub Lung: Presenting Features and Clinical Course of 21 Patients.” Respiratory Medicine, vol. 100, no. 4, Elsevier BV, Apr. 2006.
  • Wallace, William A H et al. “Inflammation-associated remodelling and fibrosis in the lung – a process and an end point.” International journal of experimental pathology vol. 88,2 (2007)
  • Oldroyd SH, Manek G, Sankari A, et al. Pulmonary Hypertension. [Updated 2022 Dec 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.

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