|
|
More than nineteen million Americans carry the factor V gene that causes blood clots, pulmonary embolism, and heart disease.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
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.
People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.