In a medical crisis it’s vital to get help ASAP. If that means a trip to the emergency room, how do you know if it’s better to drive or to call an ambulance? In some cases the decision could be the difference between life and death.

First: If you’re too sick or hurt or too distraught about a sick loved one to drive safely, pick up the phone and dial 9-1-1. An ambulance will be the safest way to get to the emergency room without crashing en route. (Note that if you’re the sick person and you’re too ill to speak, call 9-1-1 anyway. The operators can identify your location and will send help.)

Second: Call an ambulance if the injury or illness is a true medical emergency. How do you know?. Guidelines from the American College of Emergency Physicians can help you make that decision. Ask yourself these questions. If the answer to any of them is “yes,” call an ambulance:

  • Does the condition seem life threatening?
  • Could it get worse and become life threatening on the way to the hospital?
  • Will you get delayed in traffic?
  • If you try to move the person, will it likely lead to more harm?

Among the common symptoms and signs that point to a medical emergency are:

  • Shortness or breath or breathing difficulty
  • Pain in the chest or upper abdomen that lasts two minutes or longer
  • Dizziness, weakness or fainting
  • Vision changes, such as double vision
  • Speaking difficulties
  • Mental confusion
  • Sudden, severe pain
  • Bleeding that won't stop after 10 minutes or longer
  • Coughing up blood
  • Suicidal feelings
  • Severe allergic reaction, such as to an insect bite

An ambulance ride provides more than a fast trip to the ER. The paramedics or emergency medical technicians (EMTs) on board can provide pain relief en route, for example. A person who’s in shock can receive IV fluids right away. And in the event of a heart attack, “many EMTs can perform electrocardiograms as well as decide the best hospital to head to, since some medical centers offer more specialized heart and stroke care than others,” says Charles Pattavina, MD, chief of emergency medicine at St. Joseph's Hospital in Bangor, Maine. For heart attack patients, ''they would want to take them directly to the hospital that has a cardiac catheterization lab," she says.

The paramedics can also inform the ER of your condition before you arrive.

What if your wife is in labor? It’s usually safe to drive a woman in labor to the hospital, but if something seems out of the ordinary and the trip will take more than 15 minutes, it may be smart to call an ambulance, Pattavina adds.

If you call an ambulance:

  • Speak slowly, calmly and clearly.
  • Give the patient's name, the address and phone number. If you’re on the road, note the street or highway you’re on and the direction you’re traveling.
  • Briefly describe what’s going on and when the problem started.
  • Don’t hang up until you’re sure the dispatcher has all the information she needs and that you’ve followed any instructions she’s given you.

Preparing for emergencies

Medical emergencies are unexpected, but there are some things you can do to prepare for one.

  • Make sure your community is covered by the 911 system. Some rural areas are not. If yours isn’t, get the phone number for your local Emergency Medical Services and post it by your phone.
  • Organize your medical information. List the names and contact info for your regular doctors, chronic conditions such as diabetes or asthma, surgeries and hospitalizations, and medications. Keep copies at home, in your car and in your wallet.
  • If you have kids, complete a ''consent to treat'' form for each child. Make copies for the babysitter, school nurse and anyone else who cares for your children. 

Kathleen Doheny is a Los Angeles journalist specializing in health, behavior and fitness topics.