14 January 2015, 10:04 PM ET
Aquifers are underground layers of rock that are saturated with water that can be brought to the surface through natural springs or by pumping.
13 January 2015, 11:49 PM ET
Cannabis, or marijuana, is one of the oldest psychoactive substances. It is often smoked, brewed or eaten for its medicinal and recreational effects.
13 January 2015, 11:44 PM ET
Lake Vostok is one of the largest subglacial lakes in the world. It may harbor unique types of organisms.
13 January 2015, 08:13 PM ET
Frostbite is the freezing of the skin and tissue caused by excessive exposure to freezing temperatures.
13 January 2015, 06:22 PM ET
Insomnia is a sleep disorder characterized by difficulties falling or staying asleep, even though people have the chance for adequate sleep.
13 January 2015, 06:00 PM ET
Schizophrenia is a chronic, debilitating mental disorder characterized by distortions of thinking and perception.
12 January 2015, 11:46 PM ET
Seasonal affective disorder (also called SAD) is a type of depression that is often triggered by reduced daylight during winter months.
12 January 2015, 11:42 PM ET
Bulimia nervosa is an eating disorder in which people regularly binge (or overeat) and then engage in unhealthy behaviors to prevent putting on weight.
12 January 2015, 11:04 PM ET
Melanoma is a type of skin cancer that begins in the skin's pigment-producing cells, called melanocytes. These cells make melanin, which is responsible for the color in skin, eyes and hair.
08 January 2015, 08:37 PM ET
Groundwater is any freshwater that lies beneath the surface of the Earth.
07 January 2015, 10:33 PM ET
Numerous fossils make this one of the most-studied dinosaurs.
07 January 2015, 10:26 PM ET
The Mesozoic Era saw the rise of some of the most iconic animals, from Tyrannosaurus rex to birds and mammals.
07 January 2015, 10:13 PM ET
These long-lived, large windstorms are difficult to predict.
07 January 2015, 10:02 PM ET
The human heart is an organ that pumps blood throughout the body via the circulatory system.
07 January 2015, 10:00 PM ET
Heart rate, also known as pulse rate, is the number of times your heart beats per minute. A normal heart rate depends on the individual as well as a variety of factors.
06 January 2015, 09:55 PM ET
The element lithium can treat bipolar disorder and help prevent suicide, but people taking it should stay hydrated and watch for side effects.
06 January 2015, 09:42 PM ET
For many years, this dinosaur was mistakenly called Brontosaurus.
06 January 2015, 08:34 PM ET
Ayurveda is an ancient health care tradition practiced in India.
06 January 2015, 08:21 PM ET
Blood pressure is one of the vital signs that doctors measure to assess general health.
06 January 2015, 08:16 PM ET
Properties, sources and uses of the element iron.
05 January 2015, 09:51 PM ET
Leukemia is cancer of the white blood cells. It is the most common type of cancer in children, but more adults get diagnosed with leukemia.
05 January 2015, 09:40 PM ET
Properties, sources and uses of the element phosphorus.
05 January 2015, 09:24 PM ET
The anti-inflammatory painkilling drug ibuprofen is effective against fever, menstrual cramps, headaches, toothaches, joint pain and backaches.
05 January 2015, 09:18 PM ET
Ice bucket challenges aside, treatment for amyotrophic lateral sclerosis (ALS), a progressive and fatal neurological disease, is limited. However, promising research is ongoing.
24 December 2014, 11:46 PM ET
Wolf spiders are large hunting spiders that exhibit unique parenting habits.
24 December 2014, 11:33 PM ET
The term "daddy longlegs" can refer to three different types of bugs, and only one of them is a spider.
24 December 2014, 10:08 PM ET
'The kissing disease' also spreads through shared utensils and coughing and sneezing.
24 December 2014, 02:12 AM ET
The weak force is one of the four fundamental forces that govern all matter in the universe. Through the process of beta decay, it plays a crucial role in powering stars and creating elements.
23 December 2014, 11:50 PM ET
Brachiosaurus stood taller than most dinosaurs.
23 December 2014, 11:28 PM ET
There are more than 800 species of these hairy, nocturnal archnids.
22 December 2014, 09:41 PM ET
Garden spiders are the creators of the delicate, circular, spoked webs that are the classic image of a spider web.
22 December 2014, 09:23 PM ET
Since the late 1700s, the world's climate has been changing rapidly, mostly due to human causes.