Imagine you go to the healthcare provider because you have a bad cough, or maybe you fell and hurt your ribs. They want to make sure your chest is okay, so they take an X-ray or a scan. A few days later, the medical expert calls and says they found a “lung nodule.” Hearing this word can be incredibly scary. Your mind might immediately start thinking about terrible sicknesses or cancer. It is completely normal to feel very worried when you hear this news.
However, you can take a deep breath and relax. A lung nodule is simply a small spot on your lung, and it does not automatically mean you have cancer. In fact, millions of people have these tiny spots and are unaware of them. According to the Cleveland Clinic, more than 90 percent of these spots are completely harmless and are not cancerous. They are usually just tiny scars left over from a past cold or infection. Learning exactly what these spots are and how medical experts monitor them can help ease your fear.
What’s happening in your body
To understand what a lung nodule is, you can picture your lungs as two large, pink sponges inside your chest. These sponges are incredibly soft and hold the air you breathe. A lung nodule is a very small, solid lump that grows inside the lung.
For a spot to be called a nodule, it has to be quite small. It must be smaller than three centimeters across, which is about the size of a large strawberry or a thick coin. If a spot grows bigger than three centimeters, healthcare providers stop calling it a nodule and start calling it a “mass.”
As the Mayo Clinic explains, these tiny nodules are made of solid tissue, not air or liquid. Because your lungs are so large and lack feeling, you cannot feel a nodule growing. It does not hurt, and it does not make it hard for you to take a deep breath.
Common causes of lung nodules
You might be wondering how a solid lump gets inside your lung in the first place. There are many simple, everyday reasons why these spots form, and most of them have nothing to do with cancer.
“The absolute most common cause of a lung nodule is an old infection,” explains Tunde Rasheed, B.Sc. Researcher. “Throughout your life, you breathe in tiny germs, dust and even harmless fungi from the dirt. Sometimes, you might get a bad chest cold or pneumonia. When this happens, your body’s immune system fights a big battle in your lungs to kill the germs. After the battle is over and you are healthy again, your lungs form a tiny scar to heal the area. This tiny scar shows up as a bright white spot on an X-ray.”
Breathing in dirty air, heavy smoke or chemical dust at your job for many years can also irritate your lungs and cause harmless spots to form. Sometimes, sicknesses that cause your joints to swell up, like rheumatoid arthritis, can also cause your body to build tiny lumps of swelling inside your lungs, explains Mayo Clinic. While it is rare, a small number of these spots can be early lung cancer. This is why healthcare providers take every single spot seriously, just to be safe.
Diagnosis and treatment
Healthcare providers act like careful detectives to figure out exactly what lung nodules are made of. First, they will take a detailed image of your chest using a CT scanner. This machine creates a 3D picture of your lungs, showing the exact size and shape of the spot.
Johns Hopkins Medicine notes that if the spot is very tiny and smooth, the best treatment is usually doing nothing at all. The healthcare provider will ask you to come back in six months or a year to take another picture. This is called “watchful waiting.” If the spot never grows, it is just a harmless scar.
If the spot is very large, appears jagged or grows rapidly, the healthcare provider will want to perform a biopsy. This means they use a very thin needle to remove a tiny piece of tissue from the spot in your lung. They send this tiny piece to a laboratory to see if it contains cancerous cells. If it is just a harmless scar, you go home and do nothing. If the lab finds cancer, the healthcare provider will schedule a surgery to remove the spot safely.
What will a pulmonologist do for a lung nodule?
A pulmonologist specializes in the lungs and breathing problems, explains the Cleveland Clinic. If your regular healthcare provider finds a spot, they will likely send you to a pulmonologist for expert advice. This doctor will closely examine the edges of the nodule in your pictures. A perfectly round, smooth spot is usually very safe. A spot with spiky, messy edges is more suspicious.
The pulmonologist will also look at your personal life history. They will ask if you have ever smoked cigarettes, if you work around dangerous chemicals or if anyone in your family has ever had lung cancer. By putting your pictures and your life story together, the pulmonologist decides the safest plan for you. They are the experts who tell you if you can wait and relax, or if you need to have surgery.
What are early signs your body is fighting lung cancer?
Most of the time, a lung nodule causes absolutely zero symptoms. However, if a spot happens to be early lung cancer, your body might start giving you warning signs. The Centers for Disease Control and Prevention (CDC) explains that the most common early sign is a bad cough that lasts for many weeks and never goes away, even with cough medicine.
Another very serious sign is coughing up sputum with streaks of blood. You might also feel a deep, constant ache in your chest, especially when you laugh, cough or try to take a very deep breath. Finally, losing a lot of weight when you are not actively dieting or exercising is a major warning sign that your body is fighting a serious illness.
Do you need chemo after lung nodule removal?
If you have a surgery to remove a lung nodule, you might be worried about needing strong medicines afterward. The answer depends entirely on what the laboratory finds inside the spot.
If the healthcare provider removes the nodule and the lab results show it was just a harmless scar or a mild infection, you are finished and will not need any further treatments. If the spot was early lung cancer, and the surgeon was able to cut the entire thing out before it spread, you still might not need any extra medicine.
Chemotherapy is a very strong medicine used to kill cancer cells all over the body. According to the National Center for Biotechnology Information, you usually only need chemotherapy if these cells have started to break away from the nodule and travel to other parts of your chest or body.
If a healthcare provider finds a new nodule on your lung, the absolute best thing you can do is find any old chest X-rays you had in the past. If you went to the hospital five years ago for a hurt rib, ask them for those pictures! If the healthcare provider can look at an old picture and see that the same spot was there five years ago and has not grown at all, they will instantly know it is a harmless scar. This simple trick can help you avoid unnecessary tests and surgeries.
“Our lungs allow us to exchange oxygen, but they’re also filters where damaging particles can get stuck,” explains Dr. Andrea McKee, a radiation oncologist at Harvard-affiliated Lahey Hospital and Medical Center. “The more you ask your body to go through those repair processes, the more, statistically, that this damage can occur.”
When to see a doctor
Because harmless lung spots do not hurt, you will likely only find them when a medical picture of your chest is taken for a different reason. However, there are times when you should never wait.
You must call a healthcare provider or go to the emergency room right away if you suddenly have a very hard time catching your breath. You should also seek immediate help if you feel a sharp, crushing pain in your chest, or if you ever cough up bright red blood. These are serious medical emergencies that require professional help on the very same day.
Bottom line
A lung nodule is a small, solid spot on the lung that is usually discovered by accident during an X-ray or CT scan. Over 90 percent of these spots are harmless scars from old infections or dust, not cancer. By working with a lung healthcare provider to take pictures over time and watch the spot’s growth, you can safely ensure your lungs stay healthy without unnecessary worry.
Frequently Asked Questions
What are the odds of a lung nodule being cancerous?
Less than five percent of all lung nodules found turn out to be cancer, meaning the vast majority are completely harmless.
Can a cancerous lung nodule be cured?
Yes, if a cancerous nodule is found early while it is still very small, healthcare providers can completely remove and cure it with surgery.
Does lung cancer show up in blood tests?
Regular blood tests cannot find lung cancer, which is why healthcare providers must use special picture machines, like CT scans, to look inside your chest.
Citations
Cleveland Clinic. Skin Lesions: What They Are, Types, Causes & Treatment. Cleveland Clinic. Published October 17, 2022. https://my.clevelandclinic.org/health/diseases/24296-skin-lesions
Mayo Clinic. What to know if you have lung nodules. Mayo Clinic. Published 2018. https://www.mayoclinic.org/diseases-conditions/lung-cancer/expert-answers/lung-nodules/faq-20058445
Mayo Clinic. Occupational asthma – Symptoms and causes. Mayo Clinic. Published 2018. https://www.mayoclinic.org/diseases-conditions/occupational-asthma/symptoms-causes/syc-20375772
Johns Hopkins Medicine. Watchful Waiting for Prostate Cancer. www.hopkinsmedicine.org. https://www.hopkinsmedicine.org/health/conditions-and-diseases/prostate-cancer/watchful-waiting-for-prostate-cancer
Cleveland Clinic. What is a pulmonologist: When to see one & what to expect. Cleveland Clinic. Published 2021. https://my.clevelandclinic.org/health/articles/22210-pulmonologist
Centers for Disease Control and Prevention. Symptoms of lung cancer. Lung Cancer. Published February 23, 2024. https://www.cdc.gov/lung-cancer/symptoms/index.html
Amjad MT, Kasi A, Chidharla A. Cancer Chemotherapy. PubMed. Published 2023. https://www.ncbi.nlm.nih.gov/books/NBK564367/