|
|
Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.
Looking at the sun may not only cause headache and distort your vision temporarily, but it can also cause permanent eye damage. Any exposure to sunlight adds to the cumulative effects of ultraviolet (UV) radiation on your eyes. UV exposure has been linked to eye disorders such as macular degeneration, solar retinitis, and corneal dystrophies.
Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).
More than one-third of adult Americans are obese. Diseases that kill the largest number of people annually, such as heart disease, cancer, diabetes, stroke, and hypertension, can be attributed to diet.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.