The USA offers excellent health care. The problem is that, unless you have good insurance, it can be prohibitively expensive. It's essential to purchase travel health insurance if your regular policy doesn't cover you when you're abroad.
Bring any medications you may need in their original containers, clearly labeled. A signed, dated letter from your physician that describes all medical conditions and medications, including generic names, is also a good idea.
Recommended items for a medical kit:
The World Health Organization publishes regular international health advisories for travelers, along with the book International Travel and Health, available free online at www.who.int/ith/en.
It's usually a good idea to consult your government's travel-health website before departure:
No vaccinations are currently recommended or required for temporary visitors to the USA. For the most up-to-date information, see the Centers for Disease Control website (www.cdc.gov).
Health-care costs in the USA are extremely high. All travelers are advised to carry a valid health-insurance policy. Without insurance you may be billed the full cost of any care you receive. Costs can easily rise into the thousands of dollars, especially for emergency-room visits.If your health insurance doesn't cover you for medical expenses abroad, consider supplemental insurance. Find out in advance if your insurance plan will make payments directly to providers or reimburse you later for overseas health expenditures.
In general, if you have a medical emergency your best bet is to find the nearest hospital and go to its emergency room. If the problem isn't urgent, you can call a nearby hospital and ask for a referral to a local physician, which is usually much cheaper than a trip to the emergency room. Stand-alone, for-profit, urgent-care centers can be convenient, but may perform large numbers of expensive tests, even for minor illnesses.
Pharmacies are abundantly supplied, but you may find that some medications that are available over the counter in your home country (such as Ventolin, for asthma) require a prescription in the USA and, as always, if you don't have insurance to cover the cost of prescriptions, they can be shockingly expensive.
Tap water is drinkable virtually everywhere in the USA.