Unfortunately for many sufferers, lung cancer is seldom diagnosed when it is in its early stages, and is usually only discovered by accident when either a routine chest X-ray, or a CT (computer tomography) scan is ordered by a doctor for another health issue. Some 25% of all lung cancer sufferers tend to show no signs of having lung cancer present, meaning that when the disease is eventually diagnosed, it is usually in its late and final stages. Other organs in the body at this stage have also usually been caused some degree of damage. This damage is usually permanent.
As the disease develops within the lung, the outer tissues of the lung are invaded by cancerous cells, as are other nearby tissues. This development enables the lung cancer to be able to spread to other organs in the body with relative ease. The disease can infiltrate the liver and adrenal glands, which often occurs over a period of time without any noticeable symptoms to the sufferer. When symptoms of visual problems begin to occur, it is usually because the lung cancer has spread to the brain, which may cause the sufferer to have a seizure. A loss of strength may also be noticed.
Bones can also be affected by lung cancer, usually noticeable with a discomfort in either the vertebrae (backbone), or the ribs and thighs. The nerves can also be attacked, which causes many sufferers to experience continuous aching pains in the (deltoids) shoulders, and a pain that runs along the outer side of the arm. Vocal chords may be affected when the cancer has spread to the esophagus (the conduit that connects the mouth and stomach) causing difficulty in swallowing. This is usually caused when a portion of the lung has collapsed, resulting in a severe, difficult to treat lung infection.
Other common symptoms caused by lung cancer are a lack of appetite, a noticeable weight loss (usually occurring rapidly), headaches, sluggishness, memory loss problems, bleeding and clotting. These symptoms often go untreated for long periods of time before a sufferer feels the need to deal with them, as they often get associated with other less serious health issues. When a sufferer has been diagnosed with late stage lung cancer, most of the damage has already been caused to the body, resulting in a sufferer having a low prognosis (life expectancy), usually under five years from when the disease was first diagnosed.