The water may be bathed in, drunk or inhaled while massage can include aromatherapy, underwater jets, and various types of manipulation. Mud baths - known as fangotherapy - involve being covered in local clay that has been "matured" with bacteria and algae to create a biologically active and mineral-rich poultice.Different spas are famous for treating different ailments, but nearly all of them claim to be good for rheumatism and arthritis; respiratory illnesses like asthma and bronchitis; skin conditions like eczema; circulation and digestive disorders and gynaecological complaints.You can, of course, just roll up to your chosen spa and take a dip - most of the 5,000-odd springs in Europe are freely accessible. For chronic disorders such as persistent lower back pain, or gastrointestinal problems such as kidney stones, or liver and gall bladder complaints, spas are often used as a first line of treatment before more radical steps are taken.The treatment has three central components: mineral water, massage and mud. In the 17th and 18th centuries, "taking the waters" was de rigueur among England's gentry, but the practice declined with the rise of "rational" medicine, which offered instant, aggressive cures in place of slow, gentle ones.In the rest of Europe, however, spas continued to flourish and many Continental doctors still think they are just as effective for many conditions as drugs and surgery. Thermalia Travel, which specialises in spa resorts, says the number of British clients has increased tenfold in five years.The new fashion - like most - is actually a re-emergence of a very old one.

The practice of bathing in and drinking from natural hot-water springs goes back nearly 3,000 years and countless ancient cities grew up around spas, including, of course, Bath itself. Now, though, well heeled UK trend- setters are jostling to beat the Germans to the massage couches at a growing number of spa-cum-health-and-beauty centres in luxurious hotels. In Germany alone balneology - the technical name for water treatment - supports a pounds 9bn industry, much of it paid for by taxpayers. For most of this century the British have declined to take part in the sybaritic pleasures of the water cure. Millions more left private health insurers to pick up the tab. Spa "cures" are among the most commonly prescribed treatments among Italian, French and German doctors. Then they sent the bill to the country's equivalent of the NHS.