Complaints about emergency room care are legion, with stories of distress frequently voiced both by patients and by the relatives and friends who accompany them to the E.R. Sometimes these complaints are warranted, as when patients with abdominal pain wait unattended in the E.R. for hours until their appendix bursts. But more often than not, they stem from a misunderstanding of how emergency rooms operate and how patients themselves can be helpful.

Among the laments I’ve heard: “I was there four hours before I saw a doctor.” “Nurses, doctors and orderlies kept scurrying past my cubicle, but no one paid any attention to me.” “I couldn’t get anyone to bring me a drink of water.” “I was observed for hours, but no one would tell me if or when I might be admitted to the hospital.”

And if you do need to be admitted, expect to wait some more in the emergency room until a bed is available in the appropriate unit.

Each year some 120 million Americans go to an emergency room, a number that increases annually even as more hospitals close their E.R.s (there are now 22 percent fewer than 20 years ago). According to the Centers for Disease Control and Prevention, the average wait time before seeing a physician is 55 minutes, but the wait could easily exceed several hours on a busy night or weekend.

The most important fact every E.R. visitor should know is that true medical emergencies —-patients with a potentially life-threatening problem like a heart attack, stroke, respiratory distress or uncontrolled bleeding —- take precedence over a broken bone, headache or stomach pain.

A triage nurse will evaluate the severity of your problem and assign you a priority number. Expect to wait if your life is not hanging in the balance, and don’t complain if someone who came in hours after you is seen first. As one nurse put it, “Waiting is good. It means you’re not going to die.”

However, if you are waiting to be seen and your symptoms get worse or new ones develop, let the admitting desk know. E.R.s do not want people vomiting or passing out in the waiting room. But there is little to gain from exaggerating your symptoms — you’ll confuse the diagnosis and may be subjected to needless tests — in order to be seen sooner.

Also important to know: If faced with a true emergency, call 911. The responding ambulance will take you to the nearest hospital equipped to deal with your problem. Don’t follow the example of two friends of mine who walked themselves to the hospital while in the throes of a heart attack. And don’t drive or have someone drive you. If you come by ambulance, you will be evaluated and given emergency treatment immediately, even before reaching the hospital. But if your problem turns out to be less than urgent, once there you’ll be sent to the back of the line.

If a doctor sends you to the emergency room, ask the office to call ahead and provide important background information.

But think twice before heading to the E.R. for less-than-urgent problems. If your doctor is not accessible, minor ailments like a bad cold, sore throat, earache, eye infection, back pain or a cut needing stitches are best treated in an urgent care facility, now common in most cities. These days many chain drugstores have clinics staffed by medically trained personnel who can treat many minor problems, although not a bad cut or wound, and suggest more specialized care or follow-up when needed. (Do ask first about cost and insurance coverage.)

In addition, some hospitals, including most hospitals in Connecticut, have a “fast-track emergency room” for treating patients with less serious problems and getting them out quickly.

Assuming that an emergency room is your best option, there are many things you can do to make the visit more efficient and less anxiety-provoking. Along with your insurance card, keep a card in your wallet or a list on your phone with all the medications and supplements you take and any allergies or chronic health problems you have. If available, also take copies of recent laboratory or diagnostic test results.

Try to have someone come with you or meet you at the E.R. who can serve as your advocate and helpmate. A friend who recently spent many hours in the E.R. with an elderly woman who had fallen and broken her nose was able to get her a needed drink, refill her ice pack, find out when she might be admitted and offer moral support.

My friend explained, “This was a major New York City hospital where computers keep track of every patient. Everyone was very hard-working and super-organized, but not organized enough. No one told us the names of the nurse or doctor assigned to her care, or that her nurse was on lunch break and no one else could give her pain medication.

“Something should be done to calm the patient’s anxiety, as well as the anxiety of the person with her,” my friend continued. “It seems that the emotional well-being of the patient is the least thing they’re concerned about, when it should be one of the most important.”

You can save a lot of time and unnecessary tests if you know your medical history and provide it readily. If stomach pain is the reason for your visit and you’ve already had your appendix and gallbladder removed, say so right away. But don’t fault the emergency room physician for failing to accurately diagnose your problem. An E.R. doc is like a jack-of-all-trades who knows a little about many conditions but a lot about how to deal with problems that can become rapidly crippling or fatal.

Once assigned an E.R. cubicle, learn the names of the nurse and doctor in charge of your case since they are the best ones to ask for help, including pain relief, and may be the only ones who know if it’s safe for you to eat or drink something.

Although it is normal to be stressed and anxious when seeking emergency care, try to practice self-calming measures like deep breathing or meditation. This can help to minimize your symptoms and counter a tendency to become hostile, which would not endear you to the E.R. staff and may even result in less, rather than more, attention paid to your case.

When you are ready to be discharged, make sure you understand the instructions for continuing or follow-up care you may need and request a number to call if your condition worsens later.