May is a recent divorcee in her early sixties. She was working out at the gym when she began to feel queasy and lightheaded. She awoke in the back of an ambulance, and soon, she was in an ER getting blood drawn. “We need to make sure you don’t have a heart attack,” she was told.

As the day went on, May underwent test after test to “rule out” a heart attack, then a blood clot in her lungs, then a stroke. She was relieved when she found out that she didn’t have these grim problems, but she still had no idea why she felt terrible. By the next morning, she had developed a fever and was shaking with chills. It took until the end of the following day for doctors to figure out that the problem was a raging gallbladder infection. She had to undergo emergency surgery, where they found that her gallbladder had ruptured and was leaking infected fluid throughout her abdomen.

When you go to the doctor, you want to find out what’s wrong and how you can get better. In modern day America, though, what you will get are tests to “rule out” problems rather than figure out what you actually have. Patients go through x-rays and CT scans, get vials of blood drawn, and stay in hospital for days on end, then leave with a huge bill but little idea of why they feel sick or how they can get better. Not only does it leave them confused and feeling just as unwell, it often results in misdiagnosis because, as in May’s case, the focus was never on figuring out the problem to begin with.

Like the rest of America, our healthcare system has become morbidly obese. Costs are skyrocketing; we spend 18 cents of every dollar on health, a number that will rise to over a quarter by 2020. Millions of people are priced out of healthcare, with one in eight uninsured and far more underinsured. But our system is not just failing those who lack access to care. Those who have access are getting exposed to unnecessary tests with unnecessary side effects. People are going to their doctor and leaving without feeling any better.

In fact, they are getting misdiagnosed, and are suffering the consequences. Over 100,000 deaths due to medical error occur every year, and the majority of these errors are errors in diagnoses. There are growing movements to make medical care safer. I applaud these efforts to ensure surgical safety and reduce bloodstream infections, but the push for safety has to begin even earlier in the process, with getting to the right diagnosis.

Why is the diagnosis so important? First, it’s important for you to know what you have before you can treat it. You have to know what disease or process you have so you know what to expect, what to watch out for, and what you can do about it. Throwing medications at symptoms just masks them, but doesn’t get at the root of the problem. Second, not knowing what diagnoses are being considered is equivalent to searching for a needle in the haystack: it’s aimless and dangerous. Tests should be done to narrow down diagnoses, or else results are going to be obtained that don’t make sense, and you still won’t know what you have or what to do about it.

It took May a near-death experience and over a year of recovery to find out that the key to better to better healthcare hinges on getting the right diagnosis. In her case, all of the symptoms of a gallbladder infection had been there from the start. The problem was that the doctor was fixated on making sure she didn’t have other things—other problems that she didn’t even have symptoms for—and missed the boat altogether.

When you are next at your doctor, make sure you ask for your diagnosis. If the doctor is not sure, or wants to run some tests first before telling you, ask her for a list of possible diagnoses and the most likely diagnosis BEFORE you consent to the tests. Your doctor must have some thoughts on what you might have, and you should find out what that is (if she doesn’t have any clue, then that’s a problem too!).

Getting to the diagnosis is the first and most critical step to getting better, and you need to help your doctor help you. Only by ensuring that we get the best and most efficient care possible for ourselves and our loved ones can we achieve meaningful healthcare reform for the nation.

Leana Wen is an emergency physician who blogs at The Doctor is Listening. She is the co-author of When Doctors Don’t Listen: How to Prevent Misdiagnosis and Unnecessary Tests.  She can also be reached on Twitter @drleanawen.