There are no particular health concerns in the Benelux -- if you don't count the "risk" in Amsterdam and other Dutch towns of occasionally breathing in a whiff of someone else's legally tolerated hashish smoke (and of course they'd likely argue that it's perfectly healthy). You will encounter few other health problems when traveling. The tap water is safe to drink, the milk is pasteurized, and healthcare is excellent.
No health and vaccination certificates are required. You don't need any shots before your trip, but if you suffer from a chronic illness, consult your doctor before your departure. Pack prescription medications in your carry-on luggage, and carry them in their original containers, with pharmacy labels -- otherwise they won't make it through airport security. (Also, in light of recent events, travelers might want to visit www.tsa.com for up-to-date regulations on what is and isn't permissible to pack in carry-on baggage.) Carry the generic name of prescription medicines, in case a local pharmacist is unfamiliar with the brand name. Don't forget an extra pair of contact lenses or prescription eyeglasses.
Contact the International Association for Medical Assistance to Travelers (IAMAT; tel. 716/754-4883 or, in Canada, 416/652-0137; www.iamat.org) for tips on travel and health concerns in the countries you're visiting, and for lists of local, English-speaking doctors.
General Availability of Healthcare
The state-owned healthcare systems in the Benelux lands are among the world's best, even if they have begun to show signs of the strain of universal healthcare for all. It's easy to get over-the-counter medicines for minor ailments, and both local brands and generic equivalents of most common prescription drugs are available. Many doctors speak English (though the words they use might be a little disturbing, like the doctor who told me he knew what "disease" I had when I reported a minor ailment).
What to Do If You Get Sick Away from Home
If a medical emergency arises, your hotel staff can usually put you in touch with a reliable doctor. Most hospitals have walk-in clinics for emergency cases that are not lifethreatening; you may not get immediate attention, but you won't pay the high price of an emergency room visit. Embassies in Brussels and the Hague can provide a list of area doctors who speak English (meaning just about any doctor).
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.