A few months ago, the Centers for Disease Control and Prevention published a report about a young boy from Connecticut who developed lead poisoning as a direct result of his parents giving him a magnetic healing bracelet for teething. It seems every few months a story will cover a tragic case of a parent choosing an unconventional medical treatment that causes harm.

More often, the alternative treatments parents choose pose little risk to their kids — anything from massage therapy to mind-body therapies like mindfulness meditation and guided imagery. Research indicates that overall, there are few serious adverse events related to using alternative therapies. But when they do occur, they can be catastrophic, in some cases because caregivers or alternative care providers are poorly informed on how to recognize the signs of serious illness.

The National Center for Complementary and Integrative Health, part of the National Institutes of Health, now refers to these alternative treatments as complementary health approaches, or C.H.A. They are defined as “a group of diverse medical and health care systems, practices and products not presently considered to be part of conventional Western medicine.” In some cases they complement traditional care. In others they are used in place of standard medical practices.

It’s a polarizing subject that unfortunately gets muddled with conversations about anti-vaccination. But while some anti-vaxxers use complementary health approaches, people who use C.H.A. don’t necessarily doubt vaccine effectiveness.