Could a heart hole that my cousin had as a baby still be an issue now that he's 14 years old? Should we be worried about any lingering effects, or is it likely that it closed up on its own over time?

It is possible that your cousin still has a heart hole, also known as a congenital heart defect. To determine if the hole is still present, he would need to undergo medical evaluation, which may include imaging tests such as an echocardiogram. Treatment options for a heart hole may include medications such as aspirin or blood thinners, and in some cases, surgical intervention may be necessary. It is important for your cousin to follow up with a cardiologist for further assessment and management.