A shadow on the lung sometimes indicates one of several lung diseases, including cancer or abscesses. Doctors often find the shadow on a chest X-ray, ordered for other reasons, including preparation for surgery, according to The Merck Manual Home Health Handbook.
Lung abscesses are common among alcoholics. The infection begins as the individual aspirates foreign material into the lung. The onset of the symptoms is generally gradual, but the condition continues to grow worse. The individual experience fevers, cough and night sweats. Often, the lack of oxygen causes lethargy, chest pain and shortness of breath. While a potentially fatal condition, abscesses respond well to antibiotic treatment, according to Wikipedia.
The National Health System of the United Kingdom informs readers that lung cancer often appears as a white-gray mass on an X-ray. The Merck Manual Home Health Handbook reports that lung cancer is the leading cause of cancer death among men and women between the ages or 45 and 70. Lung cancer was once primarily a man's disease, but the increase in the number of women smokers has resulted in a larger number of cases of women with lung cancer.
According to WebMD, lung diseases are some of the most common types of medical conditions around the world. In the United States, millions of people suffer from lung disease. Factors responsible for most lung diseases include smoking, infection and genetics.