Doctors have long accepted that stress and health are connected (as well as stress and some things you wouldn't expect), but have been unable to completely explain it. But a new study aims to fill in some of the details by looking at the connection between stress and the common cold. Researchers exposed 276 healthy men and women to the common cold virus and waited to see how many became sick. By the end of five days, 39 percent had come down with a cold. Stressed people were twice as likely to end up sniffling, sneezing, or coughing. Researchers determined stress levels by interviewing the volunteers about psychological stress in their lives during the previous year. Much of the research on this subject has involved the hormone cortisol. During stressful situations, cortisol is released by the adrenal glands. This increase in cortisol dampens the immune system—and lowers inflammation—to free up energy to deal with potential threats. In the current study, the normal relationship between cortisol rising and inflammation falling didn’t hold for the stressed people. Researchers found that these people had become resistant to the effects of cortisol, and their bodies couldn’t control the inflammatory response as well. As a result, they were more likely to get sick when exposed to the cold virus. This research may result in a cure for the common cold one day, but it could also be useful for many other diseases that have been linked to stress and inflammation, like asthma, heart disease, and diabetes.