People with lung cancer often have related respiratory diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), or asthma. Although the prevalence of asthma (how common it is) is much higher than that of lung cancer, the two conditions share features. This finding has led some people to wonder if having one lung disease might increase the risk of developing another.

It turns out that several studies have found a positive association between asthma and an increased risk of lung cancer. This connection is especially true for certain groups and if the asthma isn’t well controlled. Just because you have asthma doesn’t mean you will develop lung cancer. Understanding what causes asthma and how to control it can reduce your risk.

Who Is Most Likely To Have Asthma?

Asthma affects around 1 in every 13 people in the United States. It’s also the most frequently diagnosed long-term disease among children in the country. People with asthma have difficulty breathing because the condition causes the airways to become narrow and inflamed. If left untreated, asthma can be life-threatening.

Some people have specific triggers that bring on their symptoms. Others are born with asthma and may have genetic links to the disease. Many different factors can increase the risk of asthma:

• Allergies — Dust, mold, or pollen can irritate the lungs and trigger an asthma flare-up.
• Air pollution — Living or working in an area with high air pollution increases asthma risk.
• Family history — Having a parent with asthma makes someone three to six times more likely to develop it themselves.
• Obesity — Excess body weight increases inflammation throughout the body, boosting the chances of asthma.
• Smoking — Smoking (and exposure to secondhand smoke) causes damage to the lungs and irritates the breathing pathways.

In addition, some people develop asthma symptoms in response to stressors like heavy exercise or a respiratory infection.

What Does Asthma Feel Like?

Asthma symptoms can vary from person to person. Some people have mild symptoms regularly (like wheezing), while others experience intense asthma attacks where they need emergency help. Asthma is often described as feeling like you’re breathing through a narrow straw.

Typical symptoms include:

• Breathing too fast or too slow
• Feeling chest tightness
• Coughing
• Having trouble catching your breath
• Waking up at night
• Wheezing

Because lung cancer and asthma affect the lungs, they can have similar symptoms. For example, both can cause wheezing, shortness of breath, and coughing. As a result, one condition can be mistaken for another. People with asthma may not notice the symptoms of lung cancer because they might assume it’s just asthma causing the problem.

Members of MyLungCancerTeam have described their experience with this issue:

“I’ve had a cough for three years,” said one member. “My doctors said it was allergies, then asthma, and when I got a new doctor after three years of coughing, he took an X-ray, which led to a CAT scan, PET scan, biopsy, and confirmation of stage 3A lung cancer. I still cough every day. It is a dry cough that sometimes leads to episodes, so I use an inhaler. I also use cough medicine, cough drops, and honey in my tea.”

What’s the Underlying Issue in Both Conditions?

Inflammation is a common driver for lung cancer and asthma. Both conditions involve inflammation of the lungs that worsens the symptoms and advances the progression of the disease. People who have ongoing inflammation of the lungs, such as those who smoke or have uncontrolled asthma, have a higher risk of developing lung cancer.

Research from the journal Cancer Medicine shows that 25 percent of all cancer cases may be caused by chronic infection or inflammation. In general, people with asthma have a 44 percent higher chance of developing lung cancer than those without asthma. Women with asthma may be especially prone to a higher risk of lung cancer development regardless of their smoking status, according to the journal Medicine.

Chronic lung inflammation causes damage and stress to the lungs. As a result, inflammation from asthma is directly linked to the development of cancer cells in the lungs. People with more severe asthma have a higher chance of developing lung cancer than those with less severe asthma. In addition, controlling asthma symptoms with medication and lifestyle changes helps lower the associated lung cancer risk.

How Can You Manage Your Risk?

There’s no cure for asthma, but keeping your symptoms under control also has a protective effect on your lungs. Your doctor can work with you on a treatment plan for ongoing asthma management. You may need to adjust the plan when your symptoms are worse, such as during allergy season or when you get a cold. Having an emergency plan is important for anyone with asthma.

Members of MyLungCancerTeam have shared stories about having asthma attacks. “Six months after my lobectomy, I’m getting back to my former stamina,” said one member. “But the summer’s persistent air pollution from fires hasn’t helped. ... I had a scare yesterday when I went to an indoor swimming pool. A woman in the locker room ignored the signs and used a crazy amount of hair spray. That induced an unusual full-blown asthma attack in me.”

Asthma may be treated with a combination of short-term medication and long-acting treatments. People with asthma may carry an emergency inhaler with them at all times to treat sudden asthma attacks. Oral corticosteroids (steroids) or inhaled corticosteroids can also provide quick relief. Short-acting bronchodilators (rescue inhalers) are commonly used for immediate symptom relief. Longer-term management may include allergy shots, long-acting inhalers, and medications that reduce swelling and help regulate the immune system. If you know what triggers your asthma symptoms, you may be able to prevent them. For example, exercising in cold weather or gardening during allergy season may be off-limits if it causes your asthma to act up.

If you’re worried about the risk of lung cancer, be sure to follow up with your health care provider. Although asthma has been linked to lung cancer, people with asthma alone (and no history of smoking) aren’t usually recommended for lung cancer screening. Nonetheless, it’s important to share any new symptoms with your doctor and explain your concerns. Keeping asthma and chronic inflammation under control may decrease your risk of developing other health problems later on.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. On MyLungCancerTeam, more than 12,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Did you get an asthma diagnosis before or after lung cancer? Share your experience in the comments below, or start a conversation by posting on your Activities page.