Is outdoor hot bathtub disease real?

In 2025, more and more people choose to install outdoor hot bathtubs at home to enjoy warm bathing time. However, the discussion about "outdoor hot bathtub disease" has gradually attracted public attention. Many people are confused when they hear the term "outdoor hot bathtub disease" and even doubt its authenticity. What is outdoor hot bathtub disease? Does it really exist?

This article will explore this issue from a scientific and medical perspective and analyze in detail the potential hazards, causes and prevention measures of outdoor hot bathtub disease.

What is "hot tub disease"?

Hot tub disease (Hot Tub Lung), also known as "hot tub lung disease", refers to a lung disease caused by specific microbial infection or allergic reaction of the human respiratory system after inhaling water vapor or aerosol in a hot bathtub. It is a rare but real respiratory disease that is mainly related to a bacterial infection called "nontuberculous mycobacteria" (NTM).

Nontuberculous mycobacteria are widely present in the natural environment, including soil and water sources. In the warm and humid environment of an outdoor hot bathtub, these bacteria can be spread through water vapor or aerosol in the air, especially when the heating system and water pump in the bathtub are running. These bacteria enter the human lungs through inhalation, causing lung inflammation and infection, forming the so-called "outdoor hot bathtub disease".

What are the causes of outdoor hot bathtub disease?

The occurrence of outdoor hot bathtub disease is usually related to the growth of bacteria and microorganisms in the outdoor hot bathtub. Here are some of the main causes of this disease:

Transmission of nontuberculous mycobacteria

As mentioned earlier, nontuberculous mycobacteria are one of the main types of bacteria that cause outdoor hot bathtub disease. They can multiply rapidly in warm water, especially in improperly maintained outdoor hot bathtubs. These bacteria are easily introduced into the air with steam and water mist when the heating and water pump are running, and enter the human respiratory tract through inhalation. Unlike traditional lung infections, nontuberculous mycobacteria usually do not cause acute symptoms, but their chronic infection may cause persistent lung inflammation and then develop into outdoor hot bathtub disease.

Water temperature and humidity in outdoor hot bathtubs

Outdoor hot bathtubs are usually kept at a higher water temperature range, usually between 37°C and 40°C, which is an environment that is very suitable for the growth and reproduction of bacteria and other microorganisms. High temperatures not only promote the reproduction of bacteria, but also spread these bacteria into the air through water vapor. Prolonged exposure to this environment and inhalation of these aerosols containing bacteria may cause lung infections or allergic reactions.

Inadequate use or failure of chemical disinfectants

Although most outdoor hot bathtubs have disinfectants such as chlorine or bromine added to the water regularly to control the reproduction of microorganisms, these chemicals tend to be ineffective or evaporate in high temperature environments. If the concentration of disinfectants is insufficient, bacteria will have the opportunity to reproduce, further increasing the risk of infection. Especially for outdoor hot bathtubs that are not regularly maintained or cleaned, the bacteria content in the water may exceed safe limits.

Use of closed environments

In some cases, outdoor or indoor outdoor hot bathtubs may be located in relatively closed spaces, such as enclosed balconies, indoor pool areas, or small courtyards. Inadequate air circulation in these closed spaces increases the concentration of bacterial aerosols. When these aerosols are suspended in the air for a long time, the amount of bacteria inhaled by users during use will also increase, which will cause the risk of outdoor hot bathtub disease.

What are the symptoms of outdoor hot bathtub disease?

The symptoms of outdoor hot bathtub disease are mainly concentrated in the respiratory system, similar to the manifestations of other lung infections or allergic reactions. Although everyone's constitution and symptoms vary, common symptoms include:

Chronic cough

People with outdoor hot bathtub disease usually have a persistent dry cough or wet cough, which is usually without sputum and difficult to relieve on its own. Cough is a chronic inflammatory response caused by infection or irritation of nontuberculous mycobacteria in the lungs.

Dyspnea

Due to lung infection, patients may feel labored to breathe, especially shortness of breath during activities. As the disease worsens, the symptoms of dyspnea may gradually worsen, and even feel short of breath when resting.

Fever and fatigue

Outdoor hot bathtub disease may be accompanied by systemic symptoms such as low-grade fever and fatigue. These symptoms are similar to other chronic lung infections. Patients usually feel weak and have reduced physical strength, which affects their daily life.

Chest pain

Some patients also experience mild chest pain, especially when taking a deep breath or coughing, which may be caused by irritation of the pleura caused by inflammation in the lungs.

These symptoms usually last for a few weeks to a few months, and they may get worse, especially if not treated promptly. Therefore, if you experience these symptoms after using an outdoor hot bathtub, you should seek medical help as soon as possible to rule out the possibility of outdoor hot bathtub disease.

Who is more susceptible to outdoor hot bathtub disease?

Although anyone can be infected with outdoor hot bathtub disease, some people are more susceptible because of a weakened immune system or other health problems. Here are some high-risk groups:

People with weakened immune systems

People with weakened immune systems, such as the elderly, those with long-term illnesses, those with AIDS, or those who have received an organ transplant, have weaker body resistance and are more susceptible to non-tuberculous mycobacteria. In addition, people with certain chronic diseases (such as diabetes, chronic lung disease, etc.) are also more susceptible to such bacteria.

Children

Children's immune systems are not fully developed yet, and they are more likely to have allergic or infectious reactions to bacteria. Therefore, families with children should pay special attention to water quality and disinfection measures when using outdoor hot bathtubs to avoid long-term exposure of children to potentially contaminated environments.

People with chronic respiratory diseases

People with asthma, chronic obstructive pulmonary disease (COPD), or other chronic lung diseases may be more likely to experience respiratory allergic reactions or infections after inhaling water vapor or aerosols containing bacteria, which may aggravate their condition. Therefore, such people need to pay special attention to water quality and ventilation when using outdoor or indoor outdoor hot bathtubs.

People with allergies

Some people are naturally more sensitive to specific microorganisms or chemicals. For people with allergies, bacteria in outdoor hot bathtubs may trigger allergic reactions and cause respiratory problems such as coughing and wheezing.

How to diagnose and treat outdoor hot bathtub disease?

If you suspect that you have outdoor hot bathtub disease, timely diagnosis and treatment are essential. Because the symptoms of outdoor hot bathtub disease are similar to other lung infections or chronic diseases, a correct diagnosis requires a series of medical tests to determine.

Lung imaging tests

Doctors usually use chest X-rays or CT scans to check the patient's lungs for signs of inflammation or infection. These tests can help doctors evaluate the condition of the lungs and determine whether there is a bacterial infection or other abnormalities.

Sputum or airway secretion testing

By collecting samples of sputum or airway secretions from the patient, the laboratory can test for the presence of nontuberculous mycobacteria infection. This is a key step in confirming outdoor hot bathtub disease.

Pulmonary function tests

For those patients with more severe symptoms, doctors may order pulmonary function tests to assess the extent of lung damage. These tests can help doctors determine whether the patient's breathing ability is significantly affected.

Treatment measures

Treatment of outdoor hot bathtub disease usually includes antibiotic treatment and symptomatic treatment. Because nontuberculous mycobacteria have certain drug resistance, treatment may take up to several months or even longer. Patients usually need to use a combination of antibiotics to ensure that the bacteria can be completely eliminated. In addition, doctors may also recommend that patients avoid continued contact with contaminated sources to avoid recurrence or aggravation of the disease.

How to prevent outdoor hot bathtub disease?

The key to preventing outdoor hot tub disease is to maintain good water hygiene and proper tub maintenance. Here are some effective preventive measures:

Clean and maintain outdoor hot tubs regularly

Keeping your outdoor hot tub clean is key to preventing bacterial growth. Change the water regularly, clean the tub surface and filter, and make sure the heating system is functioning properly.

Use chemical disinfectants appropriately

Make sure to use adequate amounts of disinfectants such as chlorine or bromine, and regularly test the chemical concentration in the water to maintain proper disinfection.

Maintain good ventilation

If the outdoor hot tub is located indoors or in an enclosed environment, ensure that there is adequate air circulation to avoid excessive concentrations of bacteria in the aerosol.

Pay attention to water temperature control

Try to keep the water temperature of the outdoor hot tub within a suitable range and not too high to avoid excessive bacterial growth.

Avoid prolonged soaking

Avoid prolonged soaking in the outdoor hot tub, especially in high temperatures, to reduce exposure to bacterial aerosols.

Does Lovia Spa offer discounts on bulk orders?

Yes! Lovia Spa offers incredible discounts and low prices for bulk orders of outdoor hot bathtubs, and swim spas. As a large-scale manufacturer, we have the capacity to produce over 1,200 units per month, allowing us to offer wholesale prices to our customers. If you're planning to purchase in bulk or need a customized quote, our team will work with you to ensure you get the best pricing. Reach out today for a free quote, bulk purchase deals, and special promotions.