A newborn gets a hearing test. Cytomegalovirus is a major cause of hearing loss in babies. iStockphoto.com hide caption

itoggle caption iStockphoto.com

After a sperm fertilizes an egg, cells divide in a stage called a blastocyst. Doctors say pregnancy doesn't start until the blastocyst implants into the woman's uterus. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Click on the map to explore geographic variations in Medicare payments per enrollee. Kaiser Health News hide caption

itoggle caption Kaiser Health News

XMRV, a mouse virus, may be an artifact of laboratory experiments rather than the cause of chronic fatigue syndrome. Whittemore Peterson Institute hide caption

itoggle caption Whittemore Peterson Institute

A Washington man talking on his cellphone may be taking a health risk, according to an analysis from the World Health Organization that finds a possible risk of cancer from exposure to the devices. Nicholas Kamm/AFP/Getty Images hide caption

itoggle caption Nicholas Kamm/AFP/Getty Images

A farmer holds cucumbers in a field in Malaga, Spain. Cucumbers from Spain have been eyed as the source of a disease outbreak in Germany. Jorge Guerrero/AFP/Getty Images hide caption

itoggle caption Jorge Guerrero/AFP/Getty Images