28 August 2014, 10:12 PM ET
People who experience social anxiety disorder are highly apprehensive in social settings, more so than the occasional case of nerves some may experience in everyday encounters.
27 August 2014, 08:12 PM ET
Post-traumatic stress disorder (PTSD) can occur after a person experiences a traumatic event, such military combat, a natural disaster, or a crisis such as 9/11.
27 August 2014, 04:38 PM ET
Chickenpox is a contagious disease characterized by many itchy, red bumps all over the body. Later in life, adults can develop a similar condition called shingles.
27 August 2014, 04:19 PM ET
People who experience generalized anxiety disorder (GAD) exhibit excessive anxiety and worry about multiple events or activities most days of the week.
26 August 2014, 10:48 PM ET
Electrical engineering is the branch of engineering that deals with the technology of electricity, including circuitry, power generation, machine control and communications.
26 August 2014, 08:48 PM ET
Autism spectrum disorder affects a person's ability to communicate, interact with others and behave appropriately in social situations.
26 August 2014, 06:06 PM ET
Dental plaque is a sticky, clear film of bacteria that forms on teeth. It causes dental problems, so plaque should be removed regularly.
26 August 2014, 02:26 AM ET
Mechanical engineers build things such as machines and tools that improve the conditions of life.
25 August 2014, 06:36 PM ET
Obsessive-compulsive disorder, or OCD, is a mental disorder characterized by persistent thoughts and ritualistic behaviors that interfere with daily life and relationships.
22 August 2014, 08:06 PM ET
Chronic lower-back pain is one of the most common complaints, but no single therapy has been proven to work.
21 August 2014, 08:40 PM ET
Engineering is the application of science and math to solve problems. It is a cornerstone of STEM education.
20 August 2014, 02:51 AM ET
Cavities, also referred to tooth decay or caries, are holes in the teeth. Cavities are the second-most common health disorder in the United States.
19 August 2014, 09:05 PM ET
Fluid dynamics is the study of the movement of liquids and gases. Fluid dynamics applies to many fields, including astronomy, biology, engineering and geology.
18 August 2014, 04:48 PM ET
Botox can be used for spasmodic muscle contraction, overactive bladder and smoothing wrinkles, and has a fairly low rate of side effects.
15 August 2014, 10:42 PM ET
Vitamin B12 deficiency is a common problem. Supplements can treat a deficiency, but doctors recommended getting vitamin B12 from foods.
14 August 2014, 08:54 AM ET
Properties, sources and uses of the element gold.
12 August 2014, 03:31 PM ET
Poison ivy is a toxic plant that causes an itchy and sometimes painful rash in most people when they touch it.
11 August 2014, 09:00 PM ET
Anorexia nervosa involves an obsession with food and weight that can end up consuming a person's life.
11 August 2014, 06:24 PM ET
Asthma is a condition in which a person's airways are inflamed, which can cause coughing, wheezing and shortness of breath.
09 August 2014, 06:32 PM ET
Carbon is one of the most abundant elements and forms a very large number of compounds, including carbon dioxide, carbon monoxide and carbon disulfide.
08 August 2014, 07:14 PM ET
Bats are the only mammals that fly. There are more than 900 types of bats, ranging in size from the flying fox to the tiny bumblebee bat.
07 August 2014, 02:00 PM ET
Seals and sea lions are semiaquatic mammals with flippers for feet. There are more than 30 species and they live all over the world.
05 August 2014, 02:03 PM ET
The coyote is a clever animal that has adapted well to growing human populations and habitat loss.
05 August 2014, 12:24 PM ET
Bobcats and lynx are cats that have stubby tails and ears topped with furry black tufts.
04 August 2014, 11:48 AM ET
The platypus is one of the most unusual creatures in the animal kingdom. It looks like it was put together from parts of other animals; females lay eggs, and males are venomous.
01 August 2014, 12:11 PM ET
They are solitary creatures that live about 7 to 12 years in the wild.
31 July 2014, 08:10 PM ET
The fourth week of pregnancy is usually when women discover they are pregnant. Now is the time to take a pregnancy test to know for sure.
31 July 2014, 07:08 PM ET
In the third week of pregnancy, there won't be any major outward changes in a woman's body, but some pregnancy symptoms may have started.
31 July 2014, 02:21 PM ET
Rams are male bighorn sheep. They have long, curved horns that they use to fight for dominance.
31 July 2014, 11:59 AM ET
Buffalo are large bovines that live in Africa and Asia. They are related to American bison, but they are different animals.
30 July 2014, 04:04 PM ET
Bears are omnivorous mammals found all over the world. There are eight species, and most of them are endangered.
30 July 2014, 12:54 AM ET
Pinpointing the exact date of conception is hard to do. Due dates are usually calculated to 40 weeks after the first day of the woman's last period.