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Author Question: Approximately __________ percent of cases of intellectual disability have no known cause. (Read 1094 times) |
According to the Migraine Research Foundation, migraines are the third most prevalent illness in the world. Women are most affected (18%), followed by children of both sexes (10%), and men (6%).
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.
Hyperthyroidism leads to an increased rate of metabolism and affects about 1% of women but only 0.1% of men. For most people, this increased metabolic rate causes the thyroid gland to become enlarged (known as a goiter).
Asthma is the most common chronic childhood disease in the world. Most children who develop asthma have symptoms before they are 5 years old.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.