A Medical ID provides information about you that may be important in an emergency, like allergies and medical conditions. When you set up your Medical ID in the Health app on your iPhone, that information is also available on your Apple Watch. If you share your Medical ID, your Apple Watch can send your medical information to emergency services when you call or text 911 or use Emergency SOS (U.S. and Canada only).
Your Apple Watch can display your Medical ID so that it’s available to someone attending to you in an emergency.