By Caroline Wyatt BBC correspondent in Paris

Demonstrations are expected in Paris and other major French cities.

The French health service is running an annual budget deficit of 10bn euros (�8bn) - a deficit the government says it is determined to cut.

The strikes come after a walk-out by French rail workers, which brought disruption to commuter train services around Paris on Wednesday.

The health strike comes a day after rail staff walked out

The French health service is currently rated the best in the world, with patients gaining immediate access to the necessary treatment.

But it comes at a high price; a price the French government says the country can no longer afford.

Despite devoting huge sums to the health service, it is running a massive budget deficit.

That is partly because French patients can go straight to the specialist of their choice - and keep going to as many doctors as they like, for as many tests as they want.

The French also take more prescription drugs than any other nation in Europe, and expect brand name drugs, not the cheaper generic version.

The government here has been cautious about tackling health reform in the past but an ageing population is now putting more pressure on the health service than ever while providing less tax revenue to fund it.