Humans

If you have a problem with your heart or liver, the diagnosis is likely to be made by a lab test or medical image. But neurologist Allan Ropper says those tests often fail when it comes to the brain.

For some survivors of head and neck cancer, the mask each had to wear to guide beams of radiation therapy remains a potent symbol. Some destroy the mask afterward. Others see a new beginning.

It's not violence on the job that makes some pro football players beat their wives or children, psychologists say. It's often childhood experience, fanned by a culture that accepts such behavior.

Tired of waiting for a cure for breast cancer, a coalition of activists now leans hard on Congress to steer money to particular research projects. Critics say that approach may miss promising leads.

Angela Stimpson donated a kidney to a complete stranger. Why did she do it? Researchers found that the brains of Stimpson and other altruists are sensitive to fear and distress in a stranger's face.