Kidney Disease

The kidneys are a pair of bean-shaped organs located in the back of the abdominal cavity right above the waist. There is one on each side of the spinal column.

Kidney Stones

The kidneys are bean-shaped organs about the size of a juice-box that are located on either side of the spine toward the back of the abdomen. They filter water, salts, and waste products out of the blood to make urine, and they maintain the body's water and ion* balance.


In the 1950s, a strange disease of the nervous system was killing people in certain tribes in the highlands of New Guinea, an island north of Australia in the Pacific Ocean. An American scientist named Daniel Carleton Gajdusek traveled to New Guinea to study the disease, which the people there called kuru.


Tanya lived outside of Tubmanburg in Liberia with her parents and four older brothers and sisters. Her family was poor, and her parents had a Many children in this West African village show signs of kwashiorkor.

Lactose Intolerance

Erin's favorite food had been ice cream since her first birthday. On her thirteenth birthday, the rocky road sundae with hot fudge went down without a hitch, but an hour later she felt awful.


During Bill Clinton's first campaign to become president of the United States, he kept losing his voice. He had developed laryngitis (lar-in-JY-tis), an inflammation or irritation of the vocal cords that makes the voice hoarse, or too soft to be heard.

Lassa Fever

Lassa fever is an infectious illness caused by a virus. It is named after the town in Nigeria where it was discovered.

Lead Poisoning

The year Josh turned 12, his parents bought a bigger house so that they would have a bedroom for his little brother, Timmy, who had just started to crawl. Everyone in the family was excited about the move to the house, which was in an older neighborhood with giant trees in the yards.

Legionnaires' Disease

In 1976, a mysterious illness affecting the lungs suddenly struck more than 200 people attending an American Legion convention at the Bellevue Stratford Hotel in Philadelphia. The illness, dubbed Legionnaires' disease, killed 34 people in this outbreak.


A disease that can cause extreme disfigurement and disability, leprosy has been among the most dreaded of diseases throughout human history. It was known to the ancient Babylonians, Hebrews, Greeks, and Romans, and is mentioned frequently in the Bible.


Sam had been looking forward to the basketball season for weeks. Now that it had actually started, though, he was having trouble keeping up during practice and in games.


Lice are tiny insects that are found on the hairy parts of the body or in clothing. A single one of these insects is known as a louse, and the eggs of a louse are known as nits.

Lung Cancer

In the 1960s, actor David McLean was hired to portray the Marlboro Man, a macho, cigarette-smoking cowboy, in television and print advertising for the tobacco company Philip Morris. McLean smoked many packs of cigarettes to get the right, ruggedly handsome look for each ad, and later he continued to receive boxes of cigarettes as gifts from the company.


"Oh, not again!" shouted 18-year-old Julia, her toothbrush falling into the sink with a clatter. It was the fifth morning this week that it had slipped from her hands.

Lyme Disease

Jill lives in a small town in Delaware that is bordered by green woods filled with deer and other wildlife. In the summer, Jill likes to spend many of her days in these woods, playing with her dog, reading, staring at the trees, and daydreaming.


Lymphoma is a general term for a group of cancers that begin in the lymphatic system, the body system that includes the tissues and organs that make, store, and carry the white blood cells that fight infections and other diseases. This system includes the bone marrow*, spleen*, and hundreds of bean-sized lymph nodes* throughout the body.


Malaria is a serious disease that once seemed to be headed for the history books. From the 1940s through about 1970, it was disappearing.

Marfan Syndrome

Marfan syndrome was first described in 1896 by the French physician Antonine Marfan. Some famous people of the past, such as Abraham Lincoln, who was very tall and lanky, and the brilliant violinist Niccolo Paganini, who had very long fingers, are believed by some to have had Marfan syndrome.


Daniel overheard his mother telling a neighbor that one of Daniel's class-mates had come down with measles. The classmate, Bianca, had recently moved from Bangladesh to the United States with her family.


In Greek, the word for membrane is "menix." This is the source of the word "meningitis," which means an inflammation of the membranes (the thin covering layers) that surround the brain and the spinal cord. These membranes are known as the meninges, and inflammation (swelling) is the body's reaction to infection or injury.

Menstrual Disorders

Kim plays soccer in the fall, plays basketball in the winter, and does gymnastics in the spring and summer. Her friends call her the "lean, mean, fighting machine," because she is almost all muscle and no fat.

Mental Disorders

A man in a tattered coat stands on the street corner, yelling at no one in particular. Although the man appears to think that he is arguing logically, his words are jumbled together and make little sense.