We might not heed a cough that won't go away or wheezing while breathing, assuming it might be because of air quality or changing weather. However, mild but chronic symptoms like these must be noted down. People often think that trouble with breathing is normal as they get older, but these might be signs of severe lung disease. With this in mind, here are six warning signs of poor lung health that should not be ignored. Chronic cough A cough that won't go away and has been around for eight weeks or longer is considered chronic. The constant symptom indicates something might be wrong with the individual's respiratory system. If one experiences this, they should visit a healthcare expert for an opinion immediately. Excessive mucus production The mucus lines the surfaces of organs like the lungs and serves as a lubricant to keep tissues from drying out and as a line of defense. But if someone develops excessive mucus in their throat or chest that won't go away, it could be a sign of lung disease. Wheezing Noisy or strained breathing is a potential sign that something might be obstructing the airwaves in the lungs or forcing them to narrow. This sign is commonly noticed in health conditions like asthma but could also occur in individuals with underlying complications like pneumonia, COPD, and bronchitis. Swelling, pain, or tenderness in legs Swelling, pain, or tenderness in the legs are common signs in people who work out or have sustained injuries. But if one experiences pain without any reason, it might be cause for concern. The symptoms might point toward blood clots in the legs. And these clots may also travel to the lungs and trigger severe problems that could threaten one's life. Blood in the cough Coughing up blood is a symptom that should be addressed by a healthcare professional immediately. The symptom might be triggered due to problems with the lungs or upper respiratory tract. The most common pulmonary reason for this symptom is bronchitis due to infection. An individual may also cough up blood if they suffer from complications like lung cancer. Bluish fingernails If one notices their fingernails turning blue, it is a potential indicator of poor lung health. The phenomenon is a sign of cyanosis, a condition where there is an insufficient amount of oxygen circulating throughout the blood. It is a telltale sign that the lungs are not as healthy as they should be because of an unsuspecting disease.