|
|
Asthma attacks and symptoms usually get started by specific triggers (such as viruses, allergies, gases, and air particles). You should talk to your doctor about these triggers and find ways to avoid or get rid of them.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
Many of the drugs used by neuroscientists are derived from toxic plants and venomous animals (such as snakes, spiders, snails, and puffer fish).
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.