For starters, a dry cough and a shortness of breath made worse by exertion are the first signs you may want to get checked out. The presence of mucus and general feelings of fatigue can also indicate infection or a more serious condition like pneumonia. However, interstitial lung disease caused by exposure to toxins can bring other symptoms like high blood pressures in the vessels of lungs, low oxygen transfer, and even gastroesophageal reflux disease. Because lung diseases are sometimes difficult to cure without immediate attention, it is important to contact your doctor if you are experiencing these symptoms.