Any of various imbalances affecting the soft lung tissue. Some common diseases of the lung include; asthma, cancer, COPD, hay fever, allergies, chronic bronchitis, pleurisy, pneumonia, and various others. Disease can cause obstructions, swelling, infections, tissue death (necrosis), wheezing, and others.

Those with lung disease often suffer shortness of breath, strained breathing, chest pain, constriction, chronic coughing, inability to travel to high altitudes, allergy like symptoms, and various others.

It has to be remembered that as the lungs are the primary source of new oxygen that lung disease immediately affects the entire body.