During deep sleep, waves of cerebrospinal fluid (blue) coincide with temporary decreases in blood flow (red). Less blood in the brain means more room for the fluid to carry away toxins, including those associated with Alzheimer's disease. Fultz et al. 2019 hide caption
New research illuminates how the measles virus may suppress the immune system after an infection. James Cavallini/Science Source hide caption
Doctors in the 1600s wore birdlike masks like these, which were thought to protect against disease. Which disease? Take the quiz and find out! Manuel Velasco/Getty Images hide caption
Arline Feilen (left) and her sister, Kathy McCoy, at their mother's home in the Chicago suburbs. The biggest chunk of Feilen's bill was $16,480 for four nights in a room shared with another patient. McCoy joked that it would have been cheaper to stay at the Ritz-Carlton. Alyssa Schukar for KHN hide caption
Vanderbilt University professor John Geer sits for a video-taped deposition in 2014, defending his expert witness report which backed up the tobacco industry position that smokers knew of the health risks of smoking as early as the mid-1950s. Academics often provide testimony for the industry. Kenneth Byrd hide caption
Sarah Zuger, who has Type 1 diabetes, with her children, Elsie and Liam, at their home in Munhall, Pa. Liam tested positive for antibodies that indicate high risk for developing Type 1 diabetes. Ross Mantle for NPR hide caption
Outside of risks from the fire's heat — and any health risks related to a long-term power outage — the main health concern in wildfire conditions is smoke, which produces particulate matter that can penetrate deep into the lungs, increasing the risk of respiratory diseases and asthma, as well as heart problems. Anna Maria Barry-Jester/KHN hide caption
Kevin Wilson's previous books include The Family Fang, Perfect Little World and Baby, You're Gonna Be Mine. Leigh Anne Couch/Ecco hide caption
Two women sit, with their faces covered, at a drug treatment center in Kabul, Afghanistan. Musadeq Sadeq/AP hide caption
Anthropologist David Graeber says there's a perverse logic that has allowed pointless jobs to proliferate in many workplaces. Yang Liu/Getty Images hide caption
Nathaly Sweeney, a neonatologist at Rady Children's Hospital-San Diego and researcher with Rady Children's Institute for Genomic Medicine, attends to a young patient in the hospital's neonatal intensive care unit. Jenny Siegwart/Rady Children's Institute for Genomic Medicine hide caption
Children attend school in the Syrian refugee camp Zaatari, in the north of Jordan, about an hour's drive from Amman. Soeren Stache/Picture Alliance/Getty Images hide caption