Chronic traumatic encephalopathy was diagnosed after his death at age 57

Also rising are costs to treat infants' withdrawal symptoms, study says

FDA: Inadequate Testing, Cleaning at Jeni's Ice Cream Plant DEA Arrests 48 in Raids Targeting Illegal Sales of Prescription Painkillers Climate Change a National Security Threat: Obama

Here are some common triggers

It can help lower blood pressure and cholesterol

Playing with guinea pig in stressful situation was calming, study finds

Study shows muscle-building exercise not as effective in women with high risk for obesity

Finding may eventually lead to test that helps determine a pet's prognosis

See a doctor if symptoms worsen or persist more than a week, physician advises

But some people are using alternative tobacco products in addition to cigarettes