DEFINITION If getting pregnant has been a challenge for you and your partner, you’re not alone. Ten to 15 percent of couples in the United States are infertile. Infertility is defined as not being able to get pregnant despite having…
DEFINITION Insomnia is a persistent disorder that can make it hard to fall asleep, hard to stay asleep or both, despite the opportunity for adequate sleep. With insomnia, you usually awaken feeling unrefreshed, which takes a toll on your ability…
DEFINITION Kawasaki disease is a condition that causes inflammation in the walls of medium-sized arteries throughout the body, including the coronary arteries, which supply blood to the heart muscle. Kawasaki disease is also called mucocutaneous lymph node syndrome because it…
DEFINITION Jet lag, also called jet lag disorder, is a temporary sleep disorder that can affect anyone who quickly travels across multiple time zones. Jet lag is caused when your body’s internal clock or circadian rhythms, which tell your body…
DEFINITION Intermittent explosive disorder involves repeated episodes of impulsive, aggressive, violent behavior or angry verbal outbursts in which you react grossly out of proportion to the situation. Road rage, domestic abuse, throwing or breaking objects, or other temper tantrums may…
DEFINITION Juvenile rheumatoid arthritis, also known as juvenile idiopathic arthritis, is the most common type of arthritis in children under the age of 17. Juvenile rheumatoid arthritis causes persistent joint pain, swelling and stiffness. Some children may experience symptoms for…
DEFINITION Inherited metabolic disorders refer to different types of medical conditions caused by genetic defects — most commonly inherited from both parents — that interfere with the body’s metabolism. These conditions may also be called inborn errors of metabolism. Metabolism…
DEFINITION Iron deficiency anemia is a common type of anemia — a condition in which blood lacks adequate healthy red blood cells. Red blood cells carry oxygen to the body’s tissues. As the name implies, iron deficiency anemia is due…
DEFINITION Dehydration occurs when you use or lose more fluid than you take in, and your body doesn’t have enough water and other fluids to carry out its normal functions. If you don’t replace lost fluids, you will get dehydrated.…
DEFINITION Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They’re normally harmless or even helpful, but under certain conditions, some organisms may cause disease. Some…
DEFINITION Contact dermatitis is a red, itchy rash caused by a substance that comes into contact with your skin. The rash isn’t contagious or life-threatening, but it can be very uncomfortable. Possible causes include soaps, cosmetics, fragrances,…
DEFINITION Conversion disorder, also called functional neurological symptom disorder, is a condition in which you show psychological stress in physical ways. The condition was so named to describe a health problem that starts as a mental or emotional crisis —…