Lung cancer can affect more than just the lungs. In fact, sometimes, the most noticeable symptoms have nothing to do with the lungs. People with lung cancer should know how the condition can affect different parts of the body. That way, they can spot problems early.

The five-year survival rate for lung cancer is 63 percent when it’s found early enough and is only in the lungs. Unfortunately, only 23 percent of cases are diagnosed at that early stage.

When lung tumors spread to other organs, the five-year survival rate drops to 8 percent. Knowing the signs that lung cancer has spread is important for finding it early.

Lung cancer can affect the body in several ways. The following are six symptoms that can result from the condition — or from other causes, including cancer treatments.

1. Fatigue and Low Oxygen Levels

Fatigue is a debilitating feeling of exhaustion. Along with physical pain, fatigue is one of the most commonly reported physical effects of lung cancer. Some of this fatigue may be caused by trouble breathing, which can lead to low oxygen levels in the brain.

Notably, fatigue and shortness of breath can be both side effects of chemotherapy, a common treatment for lung cancer. Chemotherapy can lower your red blood cell count. Red blood cells carry oxygen through your body, which helps you feel energetic. With fewer red blood cells, you get less oxygen and have less energy.

Because both lung cancer and chemotherapy can cause fatigue and shortness of breath, it can be hard to tell the cause. Is it the tumor, the treatment, or something else? For example, smoking can reduce how well your lungs work and make you feel tired, which can hide early lung cancer symptoms. Living with cancer can be very stressful, and depression can add to fatigue.

Some specialists suggest keeping a side effects journal. Each day, write down:

• When your fatigue starts
• How long it lasts
• What you were doing or eating before it began

These details can help you spot patterns and possible causes. It’s especially important to notice if your fatigue may be related to trouble breathing and low oxygen levels. For example, note whether the fatigue happens immediately or after a few days of receiving chemotherapy. In this case, it’s most likely the treatment that causes the fatigue.

Sharing these notes with your doctor can help them find the cause of your fatigue and choose the right treatment. If your fatigue is related to oxygen levels, oxygen therapy can help reduce this symptom. If your fatigue is related to your chemotherapy, your doctor can adjust your dosage, modify your treatment, or provide recommendations on how to manage this side effect.

2. Loss of Appetite

Another physical effect of cancers like lung cancer is loss of appetite, which can lead to unhealthy weight loss. “Things improved a little for my husband, but now he feels bad again and has a poor appetite,” shared one member of MyLungCancerTeam.

Approximately half of all people with cancer experience a condition called cancer anorexia-cachexia syndrome. “Anorexia” refers to loss of appetite, and “cachexia” refers to malnutrition and physical wasting.

People undergoing chemotherapy or radiation may have diarrhea, nausea, vomiting, and changes in taste, all of which can contribute to cachexia. The emotional burden of living with a cancer diagnosis can affect eating habits as well.

A poor appetite and weight loss can make daily life harder. They’re linked to more problems after surgery and to chemotherapy that may not work as well and may cause more side effects.

Medications used to treat cachexia and stimulate appetite include progestational drugs (e.g., megestrol acetate), cannabinoids such as dronabinol, and corticosteroids.

3. Coughing and Other Respiratory Symptoms

Lung cancer can also cause respiratory symptoms, including:

• Coughing up blood
• Chest pain
• Hoarseness
• Persistent cough
• Shortness of breath

“I have been coughing nonstop,” one MyLungCancerTeam member said.

Lung cancer can cause fluid to build up in the chest cavity, particularly in the space surrounding the affected lung. Known as pleural effusion, this buildup can cause shortness of breath and chest pain.

People undergoing chemotherapy or radiation therapy for lung cancer should know that both treatments can damage healthy lung tissue in the short term or the long term. This damage can lead to breathing problems.

Managing these symptoms is key to improving daily life for people with lung cancer. A plan tailored to you — combining pulmonary rehabilitation and social support — can help.

It’s easy to see how lung cancer affects breathing. But it can also cause other problems you might not link to the disease or to its treatment.

4. Cardiovascular and Lymphatic Problems

The heart and blood vessels are part of the circulatory, or cardiovascular, system. This system pumps blood through the body and delivers oxygen and nutrients to your organs. Cardiotoxicity (damage to the heart muscle) may develop after lung cancer treatment. Some heart damage can improve, but much of it does not. There are medicines that can help protect the heart and lower the risk of heart damage from lung cancer treatment.

People with lung cancer may experience other cardiovascular conditions, including:

• Coronary artery disease
• Hypertension (high blood pressure)
• Irregular heartbeat

Additionally, if your cancer has spread to your lymph nodes, you may need them removed entirely. This spread can lead to a buildup of lymph fluid called lymphedema, which can cause pain and swelling in the extremities — especially the feet and hands.

5. Spread of Cancer to the Bones

When cancer spreads to another part of the body, doctors call it metastasis. Lung cancer is among the types of cancer most likely to cause metastasis to the bone. When cancer spreads to the bone, it can cause severe pain.

Bone metastasis can cause symptoms such as:

• Weakened bones that fracture more easily
• Weakness in the arms or legs
• Trouble controlling your bowels or bladder (drom compression of the nerves in the spine)
• Hypercalcemia (increased calcium levels in the blood), which can result in constipation, nausea, and vomiting
• Joint pain

6. Headache

Lung cancer can also cause headaches — a symptom that people may not link to the disease at first. Headache is a common symptom of many conditions, including stress and dehydration. Headaches may also be a sign of more serious conditions, such as lung cancer that’s spreading to the brain or skull.

One MyLungCancer team member described the first symptoms they experienced before learning that their lung cancer had metastasized to the brain: “The only symptoms I had were headaches and zoning out in little bursts here and there, looking back on it.”

Others have discussed headache as a side effect of their chemotherapy regimen. “Headache and constipation have been the side effects of my chemo pills,” one member said.

Talk to Your Doctor

If you notice new or worsening symptoms, tell your care team. Share your symptom journal (what you felt, when it started, how long it lasted, and what you were doing) to help your doctor find the cause and adjust treatment. Ask about options to manage fatigue, appetite changes, breathing problems, heart risks, bone pain, and headaches — and whether any medication or rehabilitation programs could help.

Join the Conversation

On MyLungCancerTeam, people share their experiences with lung cancer, get advice, and find support from others who understand.

Are you living with lung cancer and worried about its other effects on your body? Do you have any symptoms that you think might be linked to your lung cancer? Let others know in the comments below.