The good news is that as smoking rates decrease and early detection rates increase, fewer people are now being diagnosed with—and dying from—lung cancer. However, the fact remains that most lung cancer goes undetected until the later stages of the disease. Read on to learn the number one most common lung cancer symptom people ignore, and which other hurdles may stand between you and a prompt diagnosis. READ THIS NEXT: If This Happens to You in the Bathroom, Get Checked for Cancer, Doctors Warn. Knowing the signs of lung cancer may lead to an earlier diagnosis, which can help improve the outcome of this frightening disease. However, early signs of lung cancer tend to be subtle, and it is most often undetectable until it has spread. That said, common symptoms of lung cancer include persistent cough, a cough that produces blood, chest pain, hoarse voice, loss of appetite, unexplained weight loss, shortness of breath, weakness, wheezing, or recurring bouts of bronchitis or pneumonia. Rarely, patients may also develop clubbed fingers, shoulder pain, and more. “Most of these symptoms are more likely to be caused by something other than lung cancer,” explains the American Cancer Society (ACS). “Still, if you have any of these problems, it’s important to see your doctor right away so the cause can be found and treated, if needed.” READ THIS NEXT: If You Do This When You Sleep, Get Checked for Cancer, Experts Say. A 2018 study published in the journal PLoS ONE analyzed the symptoms that most frequently led to a lung cancer diagnosis and noted five main symptoms that are “the most prevalent presentations” of the disease. Those were: a cough that produces blood (haemoptysis), labored breathing (dyspnoea), cough without blood, chest pain, and “constitutional symptoms,” which include weight loss, loss of appetite, fatigue, fever, and sweating. The study authors noted that out of these five main signs of lung cancer, constitutional symptoms were the least likely to lead to diagnosis. This is likely due to the fact that they are non-specific to lung cancer, and could be caused by a range of other underlying conditions. Still, their close relationship with cancer suggests that if you do experience unexplained weight loss (or another constitutional symptom), it’s important to see a doctor. Doctors say that even well-known symptoms of lung cancer, such as a persistent cough, all too often go ignored. “Lung cancer symptoms are usually mild, and they are similar to the day-to-day symptoms smokers are familiar with,” George Eapen, MD, a pulmonologist with MD Anderson’s Division of Internal Medicine, told the MD Anderson Cancer Center. “When the symptoms get severe, the cancer is advanced,” he noted.ae0fcc31ae342fd3a1346ebb1f342fcb Eapen says if you experience a cough that lasts six weeks or longer, it’s important to see your doctor—especially if you are a smoker or have a history of smoking. Do not dismiss this symptom as a normal side effect of smoking, he advises. For more health news sent directly to your inbox, sign up for our daily newsletter. According to a 2010 study published in the Journal of Clinical Oncology, diagnostic delays are common in lung cancer patients. Those researchers analyzed “missed opportunities for an earlier lung cancer diagnosis and found evidence of missed opportunities in more than one-third of 587 patients diagnosed at two institutions.” The team noted that these missed opportunities led to significant delays in diagnosis, and most often “arose from failures to recognize diagnostic clues (in most patients, abnormal imaging results).” The PLoS ONE study made a similar observation. “Over-reliance on chest X-ray findings and ignoring the patient’s prior risk could result in a missed diagnosis,” the researchers wrote, adding that this reflects a need for “better primary care access to high-resolution imaging when indicated for high-risk patients.” It also suggests that those at high risk for lung cancer may wish to follow up with a second opinion on their pathology.