Lung cancer is a complex disease that affects more than six million people in the U.S. The most common cause is smoking, but it can also affect those who have never smoked. The two general types of lung cancer include small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). While lung cancer is the leading cause of cancer-related deaths, early detection and treatment can help increase a patient’s survival rates.

While some forms of lung cancer present no symptoms, here are a few things to look out for:

1. Persistent cough

Coughing is normal as it helps free the airway of foreign objects and harmful antibodies. However, a cough that lasts for consecutive weeks or months could be due to something serious. A cough related to lung cancer can also be accompanied by chest pain and shortness of breath. While it can occur at any time, it often interferes with sleeping at night.

2. Recurring chest infections

Cancer has a tremendous effect on the immune system and because of this lung and respiratory infections become more difficult to completely recover from. This can result in a recurring infection. Oncologists advise that recurrent infections are a common part of lung cancer. If you’re suffering from chronic or recurrent chest infections, it might be time to talk to your doctor about a lung x-ray.

3. Wheezing

If you hear a whistling sound when you breathe, it’s normally a sign that your airway is blocked, inflamed, or constricted. While wheezing can occur for a number of reasons unrelated to lung cancer, it is important to take note of any changes in your breathing and report them to your doctor.

4. Back pain

This is another symptom that can be associated with a number of different conditions, however, back pain is usually one of the first symptoms accompanied by lung cancer. The pain is often caused by pressure from a tumor and irritation to the nerve roots. Back pain related to lung cancer is typically localized to the mid-upper back and typically increases in severity during the night.

5. Headaches and migraines

Headaches can be caused by a number of things, however, it can be a strong indicator of lung cancer if it is accompanied by other symptoms. Because of their location, lung tumors can place pressure on other areas of the body, including the superior vena cava is located in the upper chest region and carries blood to the upper body. When this vein becomes compressed, it can result in migraines and headaches.

The first step in treatment is diagnosis. If you are experiencing any of the symptoms above, speak with your physician about testing to increase your chances of fighting lung cancer.