The European Health Insurance card is a free card issued by your national health insurance provider that gives you access to medically necessary, state-provided healthcare during a temporary stay in EU countries, Iceland, Liechtenstein, Norway and Switzerland under the same conditions and at the same cost (free in some countries) as people insured in that country. Note that it is not the same as a travel insurance and cannot be used for private sector health care providers.
The European Health Insurance card indicates your name, your date of birth and an identification number but no medical data.
More information: European Commission Employment website.