It is good a good idea to carry an EHIC card if you are travelling in Europe but remember that it will not cover treatment at private clinics. The card offers UK residents access to state health care as though they were residents of the country they are visiting. This means that you might have to pay a contribution towards the treatment if that is the system operated in the country you are visiting. The card covers all countries in the European Economic Area and Switzerland.
The NHS website advises people to carry the card but warns against regarding it as an alternative to travel insurance.
You might not find a hospital or clinic that accepts the card and it will not cover specialist services such as repatriation. As well as covering private medical care a good travel insurance policy protects you against many other risks such as your liability if you injure someone and the loss of your personal possessions.
If you have any experience of using an EHIC card, or have any travel insurance problems let us know.