Sometimes diagnosis is straightforward. If a woman has missed several periods and has a big belly with a fetal heartbeat, it’s pretty easy to diagnose pregnancy. But most of the time diagnosis is much more difficult. Alzheimer’s can’t be diagnosed for sure until the patient dies and you do an autopsy. If only we had one of those Star Trek gadgets to point at our patients and give us a quick and accurate answer! Alas! We are far from perfect. All too often, we really have no idea what’s causing a patient’s symptoms. We do a complete workup and still don’t know. What then?

We all know people who have symptoms that a series of doctors have failed to diagnose, who continue to doctor-shop, hoping to find that one doctor somewhere who will find something the others have missed. Occasionally they do; but far more often these people spend a great deal of time and money chasing a will-o’-the-wisp. Sometimes as they are searching, the illness gradually runs its course and goes away. When this happens, whatever they tried last gets the undeserved credit for the “cure.” Sometimes the symptoms persist and these searches consume their life, encourage unhealthy self-absorption, and permanently ensconce them in the “sick” role.

One of the attractions of alternative medicine is that it offers far more certainty than scientific medicine. If your scientific doctor can’t see anything on x-rays, your chiropractor can. He’ll tell you he knows exactly what’s wrong: a subluxation that he can fix. Sherry Rogers will tell you all illness is due to toxins accumulating in your cells and you must “detoxify or die.” Hulda Clark will tell you it’s all parasites that she can eliminate with her magic zapper. Robert Young says the cause of all disease is acidosis. They all have confident, precise answers. Wrong ones.

The One Cause of All Disease?

It’s really easy to figure out what’s causing a patient’s symptoms if you believe there is one simple cause for all disease. While I was writing this I got sidetracked and searched the Internet for “the one cause of all disease.” I found a lot of them, including:

Oxygen deficiency
“Fearful, tight and negative minds”
Obstruction of ch’i along the meridians
Refined sugar
“Fault of awareness”
Grains in the diet
False beliefs and fears
Ama due to aggravated doshas
Modern medicine
Some morbid agent, producing irritation and inflammation
A “non-perceivable but very real attachment to the material aspect of creation”
Inadequate nutrition
A congested colon
“All disease is a learned experience which we can un-learn.”
“All illness is in our minds,”  and we can cure it with faith in God, meditation, or whatever.
Spiritual vital force and its dynamic derangement
Holding on to energy within the physical, emotional and spiritual bodies that is not in harmony with us
Impairment of movement of the bones of the skull
Bad health habits
Nerves too tense or too slack
Lack of life
Poor sanitation
A shock experience that catches us completely off guard
Cellular memories
An excess or insufficiency of nervous tension
Poor digestion
Weak digestive fire
Exogenous toxins
Morbid matter
An unbalanced life style
Disharmony in the equilibrium of Yin and Yang
A breakdown of the immune system
A weak “immine” system
Free radicals
An imbalance of electrons in the cellular atoms
Food abuse
Ignorance of reality
Dis-ease on any level (physical, emotional, mental, soul or spiritual) is incorrect vibratory rate(s), patterns which are not appropriate, or blocked energy pathway(s) within or between the various levels of existence
The blood
Morbid humors
Poisonous chemicals
Emotional trauma
“Allurement” of the mind by sense objects and its “willfulness” in gratifying these desires
Toxic metals
Blocked nerves
Our inability to adapt
Food acidity
Violation of natural law

And my favorite: “the United KKK States of America is the root cause of all disease…”

I’m sure there must be more, but I ran out of steam. You might ask how there can be more than one “One Cause.” Proponents of these different One Causes don’t usually fight each other. They are more likely to say that “your truth may not be the same as my truth, and that’s OK,” and “there are many realities.” But I’ll stick to the reality that science deals with, thank you very much.

If You Don’t Think There Is Only One Cause

So if all you want is a definite answer, there are plenty of (wrong) definite answers to choose from. But what if you think there might be more than one cause for all disease and you want to stick to scientific medicine?

What do symptoms mean? Sometimes they indicate a serious condition requiring urgent treatment to save life or limb. Sometimes they indicate an illness that medical science hasn’t yet figured out how to diagnose or treat. Sometimes they indicate a benign condition that will resolve on its own. Sometimes they may be due to hyper-awareness of normal body functions, or to extremes of the normal range of physiologic processes. Sometimes they represent somatization related to depression. Sometimes they are signs of malingering. Sometimes they are an excuse to talk to someone and get attention. Sometimes they are a surrogate for something else.

When I was an Air Force doctor in Spain, a sergeant’s wife came in with a whole laundry list of complaints: headaches, backaches, fatigue, you name it. I happened to know that she was a Spanish woman who had been living in the States but now she and her two small children were back living with her parents in a little Spanish village while her husband was on an unaccompanied tour of duty where she couldn’t go with him. I asked her one question: “Isn’t it hard for you to be back under your parents’ roof after living on your own in the States all these years?” She burst into tears and vented her many frustrations. We talked about how she could better cope with her difficult situation. I saw her for several followup visits. She never even mentioned her physical symptoms again and I didn’t need to do any kind of diagnostic workup.

Diagnosis Can Be Deadly

How can we decide when a symptom deserves an extensive diagnostic workup and when it doesn’t? Our strong desire to know can be counterproductive.

When I was a medical student, a patient had liver disease and was getting better. Getting better wasn’t good enough for his doctors: they wanted to know what he was getting better from. They did a liver biopsy. His disease had impaired his clotting mechanisms; he bled, he developed DIC (disseminated intravascular coagulation) and he died. Ironically, even the autopsy failed to establish the elusive diagnosis.

I heard about an Air Force general who was killed by his routine physical. He mentioned that he had frequent headaches. They sounded like typical garden-variety tension headaches, but since he was a VIP and they wanted to be sure not to miss anything, they ordered a brain scan. This was in the days before CTs and MRIs, and the brain scan they did was a fairly blunt instrument. The radiologist thought it was probably normal, but he couldn’t completely rule out the possibility of a subtle abnormality, so they proceeded to do an angiogram, injecting contrast material into his arteries, and the procedure caused a stroke and he died.

My husband’s father was killed by a routine chest x-ray, back in the days when we did annual chest x-rays on everyone. They saw a spot on his lung, thought it might be cancer, operated, found out it was benign, and then one post-operative complication led to another until he died. He didn’t need the chest x-ray in the first place, and he wouldn’t have gotten it today.

Tests Are Imperfect

Doing too many tests only increases the probability of finding a result that is abnormal but meaningless. To figure out what normal laboratory values should be, they test a lot of healthy people to create a bell curve of normal distribution. Then they cut off the ends of the curve and call the middle 95% normal. Some normal people will necessarily fall outside the “normal” lab values. If you do a panel of 20 blood tests on a perfectly healthy person, one is likely to come out positive just by chance.

A good rule of thumb is never to believe one lab test, especially if you are going to base a diagnosis on it or start treatment. My mother’s doctor tested her blood sugar and got a sky-high reading. He immediately diagnosed diabetes and prescribed medication, a diet, and home glucose monitoring. I told her not to take the medication yet, and we tested her blood glucose at home repeatedly over three weeks. Every single reading was well within normal limits! She was now labeled as a diabetic on her medical records, but she clearly didn’t have diabetes. Her doctor was skeptical of the home readings, and he ordered a Hgb A1C to double-check. It was perfectly normal.

Lab errors can occur for many reasons. Specimens are inadvertently switched or contaminated, machines malfunction, results are mis-copied. When you get an unexpected abnormal reading, it’s always prudent to repeat it.

And any test is likely to vary somewhat from day to day. If you get a cholesterol of 150 today, you might get 140 tomorrow and 160 the next day. Varying results are partly due to natural day-to-day and hour-to-hour fluctuations in physiologic functions. They are also partly due to the imperfect accuracy of the testing method. There is a margin of error for every test: I had a patient who would agonize over a rise in cholesterol of 2 points, and I tried in vain to tell her that it didn’t mean her cholesterol was up – it was within the error range of the test.

Even doctors tend to forget how imprecise our diagnostic methods really are. When a patient has a sore throat, a positive culture for Strep may not mean that Strep is the cause of the sore throat. The patient might have a viral sore throat and only be a Strep carrier. Herniated disks are seen on x-rays of many asymptomatic patients, so when someone with a backache has positive x-rays it could be just an incidental finding and his back pain might have another cause entirely.

When we do any test, we need to consider the prior probability of the disease we’re testing for. Every test has false positives. The smaller the likelihood of the disease, the less likely a positive test will mean anything.

If you have a positive mammogram, how likely is it that you actually have breast cancer? In a study in Germany, they asked doctors for their estimates. The most frequent response was 90%. Even gynecologists (who ought to have better knowledge than, say, a dermatologist) guessed 90%. In fact, only 10% of women with a positive mammogram have breast cancer on biopsy.

They taught us in medical school that in making a diagnosis, the patient’s history contributes 70%, the physical exam 20%, and the lab tests, x-rays and other procedures only contribute 10%.

Everyone wants a diagnosis. One patient was delighted that her new doctor finally figured out that she suffered from cephalalgia; all the others doctors had passed it off as a headache! (For readers who may not know, “cephalalgia” is just another word for headache, derived from the Greek so it sounds more important.)

But sometimes we just can’t make a diagnosis. For FUOs (fevers of unknown origin), a thorough diagnostic workup fails to account for 5-15%. Fortunately, these generally have a benign long-term course, especially if there are no other signs of serious underlying disease.

What Can We Do?

The general public (and some newly minted doctors) think that if you just look hard enough, you ought to be able to identify the cause of any symptom. That might be true in principle, but not in practice. A good doctor develops some judgment about what tests to do and when to stop.

I used to tell patients that the tests hadn’t picked up anything abnormal, and that I didn’t know why they were having symptoms, but I was reasonably certain that we had ruled out all the serious, potentially life-threatening causes. There were always more tests we could do, but the chance of finding anything was diminishingly small, and there was a significant chance of getting false positive results and going on a wild goose chase, possibly even including dangerous invasive tests or surgery. I would suggest that for the time being we stop worrying about “why” and simply try to deal with the situation and control the symptoms. Three things could happen:

    1.The symptoms could go away, in which case it really wouldn’t matter what had caused them.
    2.They could stay the same and we could try different ways of coping with them.
    3.They could get worse (or new symptoms could develop), in which case we could re-evaluate and consider further testing.

Most patients seemed to understand this and accept it.

It’s scary to take that course, because the lawyers are watching us, and if we ever miss anything or delay a diagnosis, we’ll see them in court. But if we really want to do what’s best for our patients, we have to know when to stop. We have to gain our patients’ confidence so they will trust our judgment and not run off on a doctor-shopping expedition or fall into the hands of quacks. We have to be willing to say we don’t know. We have to educate our patients to understand that medicine deals with uncertainties. Most of all, we have to convince our patients that we care, and that we can keep trying to relieve their suffering even when we can’t pinpoint a cause.

Posted by Harriet Hall

Harriet Hall, MD also known as The SkepDoc, is a retired family physician who writes about pseudoscience and questionable medical practices. She received her BA and MD from the University of Washington, did her internship in the Air Force (the second female ever to do so),  and was the first female graduate of the Air Force family practice residency at Eglin Air Force Base. During a long career as an Air Force physician, she held various positions from flight surgeon to DBMS (Director of Base Medical Services) and did everything from delivering babies to taking the controls of a B-52. She retired with the rank of Colonel.  In 2008 she published her memoirs, Women Aren't Supposed to Fly.