There are no particular health concerns in Amsterdam -- if you don't count the "risk" of occasionally breathing in a whiff of second-hand hashish smoke. Traveling in the Netherlands poses few health problems. The tap water is safe to drink, the milk is pasteurized, blood for transfusions is HIV-screened, and you likely won't need to worry about getting too much sun.
If You Get Sick -- If a medical emergency arises, your hotel staff can usually put you in touch with a reliable doctor. If not, contact the Central Doctors Service (tel. 020/592-3434; www.centraldoctors.nl) or go to the emergency room at one of the local hospitals. The U.S. and U.K. consulates in Amsterdam can provide a list of area doctors who speak English (almost every doctor in town). Most Amsterdam hospitals have walk-in clinics for emergency cases that are not life-threatening, though you may not get immediate attention.
General Availabilty of Healthcare -- The Dutch healthcare system is among the world's best. It's easy in Holland to get over-the-counter medicines and other simple remedies for minor ailments. Local brands and generic equivalents of common prescription drugs are available. Most doctors speak English (though their lingo might be a little disturbing, like when a doctor once told me he knew what "disease" I had when I reported a minor ailment).
Watch for pickpockets on trams, buses, Metro trains, and in train and Metro stations. Constant public announcements at Centraal Station and Schiphol Airport warn about pickpockets, and tram signs warn, in a multitude of languages, ATTENTION: PICKPOCKETS. Drivers often recognize a pickpocket who gets on their bus or tram, and announce over the vehicle's PA system that passengers should watch out for their belongings. It's fun to watch the miscreants getting off again at the next stop, foiled. Pickpockets and other thieves often wait until you are occupied or distracted -- or act to occupy or distract you -- before making their move. Consider wearing a money belt. Women, wear your purse crossed over your shoulder so that it hangs in front, with the clasp or zipper facing in. A backpack worn on the back is an open invitation to thieves, so either don't wear it like that or don't put anything valuable in it (you could consider packing it with loaded mousetraps).
Violence is not unknown to Amsterdam, but it's not at all a violent city. Foreign drug dealers whacking each other doesn't count -- unless innocents get caught in the crossfire, this usually merits only a single-sentence news blip on p. 21 of the local paper. Drug-related crime is prevalent, but most of it, like pickpocketing, is nonviolent, relatively minor, and opportunistic. Stealing bicycles is a "big" problem her. Muggings and armed robberies do happen, but they're not a regular feature of life.
There are some risky areas, especially in and around the Red Light District. Be leery of walking alone after dark through narrow alleyways and along empty stretches of canal. Don't use ATMs at night in quiet areas. It's wise to stay out of Vondelpark at night, but there are cafes on the edge of the park that are busy until closing time.
Amsterdam has its share (more than its share, really) of weird folks, some of whom may lock onto you for one reason or another. If you can't shake them off, go into a cafe or hotel and wait until they leave or call a taxi to take you away.
Report any crime committed against you to the police (politie), most of whom speak English and are generally helpful to visitors.
Note: Listing some of the possible dangers together like this can give a false impression of the threat of crime in Amsterdam. There is no need to be afraid to do the things you want to do. Amsterdammers aren't. Just remember to exercise the usual rules of caution and observation that apply in any big city.
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.