|
|
Complications of influenza include: bacterial pneumonia, ear and sinus infections, dehydration, and worsening of chronic conditions such as asthma, congestive heart failure, or diabetes.
For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.
Only one in 10 cancer deaths is caused by the primary tumor. The vast majority of cancer mortality is caused by cells breaking away from the main tumor and metastasizing to other parts of the body, such as the brain, bones, or liver.
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.