19 Silent Lung Cancer Symptoms You Need to Be Aware Of

Lung cancer is the leading cause of cancer death in both men and women, according to the Lungevity Foundation. The disease claims the lives of approximately 156,000 Americans annually—and though you might feel like you're immune to this illness if you're a nonsmoker, the reality is that an estimated 20 percent of people who die from lung cancer have never smoked or used tobacco products. Anyone can get this deadly disease, which makes it all the more important to know what to look out for when it comes to the warning signs. Here are some of the symptoms of lung cancer that everyone should know.

In some cases, lung cancer develops on an area of the lung called the superior pulmonary sulcus. When these tumors occur, more telltale signs like coughing don't appear until late in the disease. Instead, "the most common initial symptom that can be present in up to 96 percent of patients … is shoulder and arm pain," says Francesco-Maria Serino, MD, PhD, the founder of Doctors in Italy.

Tumors called Pancoast tumors are defined by their ability to affect nearby tissue, meaning they sometimes cause a group of nerve-related symptoms known as Horner syndrome, according to the American Cancer Society. The symptoms of Horner syndrome include drooping or weakness of one upper eyelid, a smaller pupil in the affected eye, and little or no sweating on the affected side of the face.

Lawrence Shulman, DO, chief of the division of pulmonary and sleep medicine at ProHEALTH Care, says that if you've received a recurring diagnosis of pneumonia in the same area of the lung, it could be a sign of lung cancer.

On their website, Johns Hopkins Medicine also notes that any recurring respiratory infections could be a symptom of lung cancer, so make sure to consult your primary care provider if you feel like you're getting sick particularly often.

Don't immediately assume that chest pain is indicative of heart issues. The lungs are lined by a membrane called the pleura, and according to Michael Chen, MD, an internal medicine physician with Ezra, "if lung cancer is irritating this lining, it can cause pain that you feel in your chest."

According to Chen, "your immune system can recognize lung cancer and then produce an antibody response that causes an autoimmune disease called Lambert-Eaton myasthenic syndrome (LEMS)." This disease causes the body to attack its own tissues in the area where nerves and muscles meet, which results in muscle weakness.

"The vena cava is the major vein that drains deoxygenated blood back into your heart," explains Chen. However, when a tumor in your lung gets big enough, it can physically compress the vena cava. This phenomenon, known as superior vena cava syndrome (SVCS), causes decreased blood flow to the heart and the rest of the body, which can result in swelling in the face, neck, upper body, and arms.

Lung cancer can sometimes lead to hormonal imbalances that cause Cushing's syndrome, a disorder characterized by too much cortisol in the bloodstream, Chen says. A symptom of this syndrome is the face becoming rounder and wider, also known as "moon face."

Finger clubbing—which is defined by club-like changes in the shape of your fingers and fingernails—can be a sign of lung cancer, according to Cancer Research UK. Thirty-five percent of people with non-small cell lung cancer experience this symptom.

Finger clubbing happens in stages: First, the nail bed becomes soft and the skin next to the nail bed is shiny; then the fingernails curve more than normal; and finally, the ends of the fingers become larger until they're bulging.

Shortness of breath is often attributed to age or a sedentary lifestyle. However, oncologist Adil Akhtar, MD, notes that in some cases, this can be a silent sign of lung cancer.

A cough that won't go away is certainly unpleasant, but it doesn't necessarily raise alarm bells (especially during cold and flu season). However, Akhtar says that an unrelenting cough is something to be taken seriously. "A chronic cough [can be] due to irritation caused by cancer," he notes, adding that it can also be a symptom of other more common lung disorders.

"Fatigue can be an early symptom that is not commonly attributed to lung cancer," Akhtar says. Even if your tiredness isn't due to lung cancer, this can be a sign of other illnesses and chronic conditions, and it isn't something that should be ignored.

Lung cancer can literally have an impact from head to toe. According to Andrea McKee, MD, American Lung Association's national spokesperson, the disease can spread to the brain and cause headaches, seizures, memory loss, and personality changes.

"Lung cancer can spread to the bones," explains McKee. Indeed, the Rogel Cancer Center at Michigan Medicine notes that this type of cancer is one of the most common culprits of bone metastasis, as it's called. These "bone mets" often result in weakness that can lead to fractures.

"Blood clotting disorders can happen in anyone who has an underlying cancer," says McKee. And they do: According to the North American Thrombosis Forum, blood clots occur in as many as 20 percent of cancer patients.

"[A] tumor invading blood vessels in the lung can cause hemoptysis or coughing up of blood," says McKee. Coughing up blood is never a good sign, so head to the doctor straight away if you notice that your phlegm is red.

According to the American Cancer Society, unexplained appetite loss and weight loss can both be signs of lung cancer. However, these symptoms are commonly seen in patients with other chronic illnesses, so talk to your doctor before jumping to any conclusions.

If you or others notice that your voice has become more hoarse, raspy, or high-pitched, The Lung Cancer Foundation of America recommends getting checked out because they could be lung cancer.

Dizziness or limbs that become weak or numb are signs of lung cancer that tend to emerge once the illness is in its advanced stages, according to The Cancer Treatment Centers of America. Other symptoms that are more common during these advanced stages are jaundice and lumps in the neck or collarbone region.

Many people with lung cancer experience high levels of calcium in their blood, according to the American Cancer Society. As a result, lung cancer patients often deal with insatiable thirst and a constant need to urinate.