Episode 47: September 26, 2012
by Rob Lamberts, MD
Today's article explains how doctors diagnose those patients with unusual symptoms.
Unlike the drama on television with that other doctor who has the word “House” in his name, the patient is on center stage in the exam room, not the doctor. So your participation is key to getting to the bottom of any unusual symptoms you might have. The purpose of this article is to give you insider information on what doctors do when presented with a mystery condition. The next time you're the one with the unusual condition, you'll know what to expect at the doctor's office.
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Diagnosis Step 1: The Chief Complaint
The star of today’s show is Frank, a 42 year-old man who comes to the office for a cough.
My first important question is: Why does this person want medical attention? Doctors call this reason for the visit the chief complaint. Sometimes it is easy to figure out why a patient decided to spend the time and money to see the doctor, but other times it isn’t. When patients say “I’m sick” or “I don’t feel right” as their reasons for coming in, my job is to get more specifics.
Our man came in for a cough, but most people with a cough don’t come to see the doctor. In this case, Frank says he came in because he’s had the cough for two months. So in his record, I write his chief complaint as cough x 2 months.
Diagnosis Step 2: The History
The next step is to listen to the patient’s story, or in doctor speak: the history of present illness (or HPI). To be sure I come to an accurate diagnosis, I need to listen to the story Frank tells without jumping to conclusions. I need to gather as much data as possible before taking the next step.
But not all patients are good storytellers, so there are a series of questions doctors ask to try and elicit the information they need:
When did the symptom start?
Has it been continuous or intermittent?
If it is intermittent, how often does it happen and is there any time of day it is likely to happen?
How bad is it?
What is the character of the symptoms?
Does anything make it get better or worse?
Have you taken any medications for it?
Have you ever had symptoms like it before?
When the doctor asks these questions, he or she is listening for a pattern. Pattern recognition is one of the most important ways to figure out the cause of mystery symptoms. Be ready to answer these questions when you go to the doctor and answer them as accurately as possible. Really think about the question because the doctor can not properly diagnose you without your help.
In this case, Frank has continuously coughed for the past two months. The cough hasn’t been terrible; it’s just a really annoying dry cough that won’t go away. He’s tried over-the-counter cough drops, but they don’t seem to help. He’s never had symptoms like it before.
Diagnosis Step 3: The Review of Systems
Pattern recognition is one of the most important ways to figure out the cause of mystery symptoms.
The next step, the review of systems, is when the doctor looks for important symptoms associated with the problem. I’ll ask Frank questions related to the other parts of his body, from general symptoms like fever and fatigue, to symptoms related to specific body parts, such as nasal congestion, earache, abdominal pain, and joint pains. It may seem crazy to ask questions about your eyes when you are there for joint pain, but there are many occasions when the answers to these questions end up being helpful.
Frank is not having fever, shortness of breath, nasal congestion, sore throat, or wheezing, but he is having occasional heartburn.
Diagnosis Step 4: Other Histories
Next the doctor looks at any other important facts about the patient. There are three main areas doctors consider:
The past medical history - which includes any medical conditions, past or present, the person has, and what medications they are taking.
The social history - which covers their work and home situations, hobbies, and their personal habits, such as smoking, drinking, and exercise.
The family history - which covers significant conditions that run in the family, like cancer, heart disease, and other conditions.
In this case, Frank has high blood pressure and is taking a medication for it. He’s also had problems with esophageal reflux, which got better when he lost weight. He hasn’t had asthma or allergies. Frank is a firefighter, has a pet parakeet, and doesn’t smoke. His family history is negative for asthma.
Diagnosis Step 5: The Exam
Once we’ve done all that data-gathering, doctors finally get to the physical exam. By the time I examine people, I have a good idea of what I am looking for, but I still try to do a thorough exam. In this case, I pay very close attention to Frank’s lung exam, listening for anything abnormal. His exam is entirely normal.
Diagnosis Step 6: The Differential
So now we come to the climax of the drama. How does the doctor put all of these pieces together to make a diagnosis? Does the doctor fall prey to his prescription drug addiction and miss important facts? How many people will the doctor insult in the process?
Actually, it’s not quite that dramatic. The real next step is to do something simple: make a list. Doctors call this the differential diagnosis, which basically asks two questions:
What are the bad things that I have to rule out?
What are the other things that could cause the symptoms?
The ability to build a good differential is key to being a good diagnostician. For a chronic cough, lung cancer and tuberculosis are the two main bad things I need to rule out. Since Frank is young and a non-smoker, the risks are quite low and therefore worth considering only after more common things are ruled out. There are four common causes of a chronic cough:
Drainage from the sinuses
Medications (specifically, a very common blood pressure medication called an ACE inhibitor is associated with an annoying dry cough.)
In this case, the patient has no drainage from his sinuses, and doesn’t have asthma. That doesn’t rule these things out, but it does make them less likely. He is a firefighter, so his exposure to smoke could make him more susceptible to lung symptoms. He does have heartburn occasionally, so reflux is still on his list. My initial suspect, the blood pressure medication, turns out being innocent, as he is not taking an ACE inhibitor.
The Mystery Diagnosis
So we are left with reflux being the top thing on the list, with sinus drainage and asthma being much lower down. Instead of ordering a chest x-ray, or other expensive tests, which wouldn’t help with any of these problems, I would treat Frank for reflux and see whether his cough went away. If it does go away, we’ve got our answer; if it doesn’t, then more work-up is required.
Well, he didn’t get better after two weeks of the reflux medication, Prilosec, so I examined him again and this time noted a piece of dirt in one of his ear canals that I must have missed before. When I attempted to remove it, he coughed uncontrollably, so we had to wash it out with water. After that, his cough went away.
There is a nerve in the ear, called Arnold’s Nerve, which is a branch of the nerve that controls the diaphragm. In some people, stimulation of this nerve will make them cough. I’ve actually seen this a few times in my office.
Now you know all of the steps a doctor must go through to diagnose you. My advice for you, as a patient, is to be prepared for these steps before you actually see the doctor. That way you can give the doctor all of the important information they need to make an accurate diagnosis.
Click here to read the second installment in my mystery diagnosis series, in which I get to the bottom of a patient's dizziness.
If you have topics or mystery diagnoses, that you want me to discuss, send them to email@example.com, or you can submit them to me on Twitter or my Facebook page.
Let me once again remind you that this article is for informational purposes only. My goal is to add to your medical knowledge and translate some of the weird medical stuff you hear, so when you do go to your doctor, your visits will be more fruitful. I don’t intend to replace your doctor; he or she is the one you should always consult about your own medical condition.
Catch you next time! Stay Healthy!