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The varicella zoster virus causes chickenpox in children, then lurks in the body for years and can cause painful shingles later in life. James Cavallini/Science Source hide caption

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Solid information on the risks of medications during pregnancy is often hard to come by. iStockphoto hide caption

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Ten-year-old Jake Herrera and his Los Angeles team run around the diamond as a warmup for baseball practice. Benjamin B. Morris for NPR hide caption

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Keith Negley for NPR

Painting iStockphoto hide caption

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Some researchers recommend starting mammogram screening at age 40, while others say age 50. Some doctors think screening should be based on a woman's overall risk for breast cancer, not just her age. Hero Images/Corbis hide caption

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NPR senior Washington editor Beth Donovan walks on a treadmill desk in her office in Washington, D.C. Meredith Rizzo/NPR hide caption

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