Sometimes it’s tough to know what to do when a medical condition or complaint arises. People often ask themselves: Should I talk to my doctor? Should I just ignore what’s happening? Is this serious enough to call 911?

I’ve been an emergency department doctor for 25 years. In that time I’ve seen thousands of people in routine situations and life-threatening ones. Based on that experience, I always share three guidelines with patients and friends who ask, When should I seek medical aid?

First, call a doctor if you ever have any doubts about a health situation. This is especially true if what’s happening is unfamiliar or confusing. A physician’s guidance can ease your mind or direct you to care when you or a loved one need it most.

Second, call 911 if you experience something that is abnormal for you and clearly could kill you or cause extensive bodily harm.

Third, always err on the side of caution. Assume that you need help. Act accordingly. Too often, people delay getting aid and lose precious minutes when care is necessary.

These three pieces of advice recognize that everyone does not experience a disease or condition exactly the same way. For example, heart attacks can vary greatly from patient to patient. Classic symptoms include chest pain, nausea, shortness of breath, and pain that extends to arm, teeth and jaw. However, some patients, especially women, feel pain in the abdomen, shoulders, and back. Many people believe that heart attack pain will only appear in the left arm. Yet it also can affect the right one. TV and movies suggest that heart attacks always are dramatic events. They aren’t. In short, if you have any reason to believe you’re having a heart attack, call for emergency help.

Likewise, if you believe a stroke has occurred, call 911. A stroke happens when the blood supply to the brain stops or drops. This keeps oxygen and nutrients from reaching brain tissue. If this happens, cells start dying. Like heart attacks, patients experience strokes differently. However, common symptoms include stumbling, dizziness, and loss of balance or coordination. Speaking and understanding spoken words become difficult. Confusion, blurred vision, headaches, and nausea also can occur. Paralysis or numbness may happen suddenly. A stroke is an emergency. Speed is vital. Seek professional help the instant you believe a stroke may have occurred.

I can’t describe every instance when a trip to the emergency department is necessary. However, some situations are so clear cut and dire that a 911 call always is required. So seek help if you or someone with you suffers from: a coma; drug overdose; bloody diarrhea; broken bones, especially if they’re exposed; chest pains; confusion; dizziness; drowning; heat stroke; numbness; profuse, unstoppable bleeding; serious burns; severe allergic reaction; severe stomach pain; shortness of breath; sudden blindness; sudden nosebleed; sudden slurred speech; tingling; or vomiting blood.

If you call 911, remain calm. Be prepared to describe the medical situation. Do so in detail because this can help emergency technicians and doctors begin treatment sooner. Mention any conditions or medicines a patient has or takes. Describe the situation surrounding the call. For example, if a patient is injured in a car wreck and other drivers are involved, say so. That way, the dispatcher knows to send police, firefighters, and a properly-equipped ambulance. Emergency vehicles often are prepared to deliver either basic or advanced care. It’s important that the right type arrives on the scene.

Let me offer one final piece of advice regarding 911. Please do not drive yourself or another patient during an emergency. Here’s why. First, traffic may delay you. An ambulance with flashing lights and a siren can move more quickly than anything else on the road. Second, time may be vital. Ambulance teams can start care the instant they arrive, which always works to the patient’s advantage. Third, if you’re the patient, you may not be physically able to make it all the way to the emergency room.

Of course, most of the time most of us will not require emergency aid. So that begs the question: When do I call my primary care physician? As I said earlier, call whenever you need information. Logical times to talk to your doctor include when you:

• want a physical exam;

• need ongoing treatment for a condition;

• require refills on medications;

• suffer from routine sniffles, colds, minor injuries, and the flu.

Finally, please keep in mind the old adage: an ounce of prevention is worth a pound of cure. To keep trips to the doctor and the emergency department to a minimum, remember to exercise, eat wisely, follow prescriptions precisely, act with care at home and on the road, and get flu shots and checkups regularly.

Audrey L. Grant, M.D., FACEP serves as emergency department director of Bon Secours Maryview Medical Center in Portsmouth.