Understanding Lung Cancer

Signs and Symptoms of Lung Cancer

Last updated and reviewed on May 15, 2026. 

A symptom is something you feel or notice in your own body, like pain, tiredness, or a cough that will not go away. A sign is something a doctor can observe or measure, such as an abnormal result on an X-ray or a change in your breathing sounds during an exam. Lung cancer can cause both signs and symptoms, but one of the most challenging things about this disease is that it often causes no noticeable signs or symptoms in its early stages. Many people feel completely normal for months or even years while the cancer is quietly growing.

Because the lungs do not have many pain-sensing nerve endings, small tumors can grow without causing discomfort. This is why lung cancer is so often found at a later stage, when it has already grown large or spread to other parts of the body. In fact, about 40% of people with lung cancer are not diagnosed until the cancer is already in an advanced stage. This is one of the most important reasons why lung cancer screening is recommended for people at high risk to try to catch the cancer before any symptoms appear.

When symptoms do appear, they can easily be mistaken for other, less serious conditions like a common cold, allergies, acid reflux, or a chest infection. A cough might seem like a seasonal allergy. Shortness of breath might be blamed on being out of shape. Fatigue might be tied to a busy schedule. Because of this, many people put off seeing a doctor, not realizing that these everyday-seeming symptoms could be a sign of something more serious.

What are the signs and symptoms of lung cancer?

The most common symptoms of lung cancer

• Coughing up blood, even a small amount, is one of the most important warning signs of lung cancer. The blood may appear as bright red streaks mixed into mucus or phlegm, or it may look rust-colored or dark. While coughing up blood can have other causes like a bad respiratory infection or bronchitis, it should never be ignored and always warrants a call to your doctor. Even a single episode of coughing up blood is reason enough to seek medical evaluation.

• Shortness of breath is another very common symptom. It may develop gradually, making it easy to dismiss as a normal part of getting older or being less active. But if you find yourself getting winded doing things that used to be easy, climbing a flight of stairs, walking to the mailbox, or even getting dressed, that change in your breathing capacity is worth discussing with your doctor. Lung cancer can cause shortness of breath by blocking an airway, causing fluid to build up around the lung, or replacing normal lung tissue with cancer cells that do not exchange oxygen properly.

• Chest pain that is persistent, especially pain that worsens when you breathe deeply, cough, or laugh, is another common symptom. This pain is often described as a dull ache rather than a sharp stabbing pain, and it may be felt in the chest, shoulder, or upper back.

• Hoarseness, a raspy or strained-sounding voice, can occur when a lung tumor presses on the nerve that controls the voice box.

• Unexplained weight loss and loss of appetite are also common and important warning signs. Losing 10 pounds or more without trying is something doctors take seriously. The cancer uses a great deal of the body's energy, and substances released by cancer cells can suppress appetite and cause weight loss even before other symptoms appear.

Less Common Symptoms of Lung Cancer

Beyond the most well-known symptoms, lung cancer can cause a range of less obvious signs that are easy to overlook or attribute to other causes. These less common symptoms are important to know because, in some cases, they may appear before the more typical respiratory symptoms do, or they may be the only sign that something is wrong.

• Wheezing, a high-pitched whistling sound when breathing, can occur when a tumor partially blocks an airway, causing air to squeeze past a narrowing. While wheezing is commonly associated with asthma or allergies, wheezing that is new, unexplained, and happening in only one area of the chest can be a sign of a blockage caused by a tumor.

• Repeated lung infections, such as pneumonia or bronchitis that keep coming back in the same part of the lung, should raise a red flag. A tumor can block part of an airway and prevent mucus from draining properly, making that area of the lung vulnerable to repeated infections.

• Swelling of the face, neck, or arms can occur when a lung tumor presses on a large vein called the superior vena cava, which carries blood from the upper body back to the heart. This is called superior vena cava (SVC) syndrome. It can cause a feeling of fullness or pressure in the face, visible swelling, and sometimes a bluish tint to the skin. This symptom is more commonly seen with small-cell lung cancer and requires prompt medical attention.

• Difficulty swallowing is another less common symptom that can occur if a tumor presses on the esophagus (the tube that carries food from the throat to the stomach) or affects the nerves involved in swallowing.

• Paraneoplastic syndromes are a group of symptoms caused not by the tumor pressing on something, but by substances the tumor releases into the bloodstream that affect other systems in the body. These can include muscle weakness, difficulty walking, confusion or memory problems, numbness or tingling in the hands and feet, and even hormonal changes that lead to symptoms like high blood calcium, low sodium levels, or unusual fluid retention. These effects can sometimes appear months before a lung cancer diagnosis is made.

• Finger clubbing, a gradual rounding and widening of the fingertips and the nails curving downward, is a physical sign that has been linked to lung cancer and other serious lung conditions. It happens when there is a lack of oxygen in the blood over time and is rarely noticed right away.

• Fatigue that does not improve with rest is also worth mentioning. It is a very general symptom, but one that many lung cancer patients report as one of the first things they noticed before their diagnosis. While tiredness alone is rarely a sign of cancer, fatigue combined with other symptoms on this list is worth bringing up with your doctor.

Symptoms of Advanced (Metastatic) Lung Cancer

When lung cancer spreads beyond the lungs to other parts of the body, it is called advanced or metastatic lung cancer. At this stage, symptoms are caused not only by the tumor in the lung, but also by cancer cells that have traveled through the bloodstream or lymph system and formed new tumors in other organs. The symptoms of metastatic lung cancer depend on where in the body the cancer has spread, and they can range from mild to very serious.

• The brain is one of the most common places where lung cancer spreads. When this happens, symptoms can include persistent headaches (often worse in the morning), dizziness or problems with balance, vision changes such as blurriness or double vision, confusion or difficulty concentrating, memory problems, personality or mood changes, and weakness or numbness on one side of the body. In some cases, metastatic cancer in the brain can cause seizures. These neurological symptoms can appear suddenly and should be treated as a medical emergency.

• Bones can cause deep, aching bone pain that is often worse at night or with activity. The spine, hips, ribs, and upper leg bones are the areas most commonly affected. Bone metastasis can also weaken the bones and make them more likely to fracture, sometimes from just a minor bump or fall. High calcium levels in the blood (called hypercalcemia) can also result from bone metastasis and may cause symptoms like extreme thirst, frequent urination, constipation, nausea, and confusion. Hypercalcemia is a serious condition that requires prompt treatment.

• Liver cancer can interfere with the liver's ability to process waste products from the blood. This can lead to jaundice, a yellowing of the skin and whites of the eyes, as well as upper right belly pain, bloating, nausea, and poor appetite.

• Adrenal glands sit on top of the kidneys and do not usually cause noticeable symptoms early on, but they can affect hormone production and may be discovered during imaging tests.

• Lymph nodes in the chest, abdomen, or neck can cause swollen glands that may be felt as lumps under the skin.