There are two medical conditions that come up very frequently in consideration of panic disorder. They are said variously to be confused with the disorder because of a similarity of symptoms or to be related to it because they occur together. They are reactive hypoglycemia and mitral valve prolapse. The more important condition is reactive hypoglycemia.
Hypoglycemia means low blood sugar. It is not an illness but simply a physical finding. It can be caused by a number of conditions of varying seriousness, and in turn can cause a variety of symptoms which seem at first glance to resemble those of a phobia. These include lightheadedness, shakiness, sweating, weakness and fatigue, nervousness, fast heart- beat, blurring of vision, and tingling of lips and tongue- among others. They are relieved promptly by raising the blood sugar to a proper level. The terms “reactive hypoglycemia” or “functional hypoglycemia” are used vaguely to refer to a condition in which someone for undiscovered, or undiscoverable, reasons overreacts to the ingestion of sugars by a rise and then an abrupt fall in blood sugar levels, precipitating the symptoms listed above.
There is some doubt about whether reactive hypoglycemia actually exists. There is no question that the great majority of times the diagnosis is made, it is made in error. Anxious people (often phobics who are concerned about the possibility of suffering some obscure physical illness) come to the attention of a careless physician who performs a glucose tolerance test and without further investigative procedures informs them that they have hypoglycemia, which will have to be treated by eating five or six meals a day for the rest of their lives. Or the patients may be self-diagnosed, matching up their symptoms with those described for hypoglycemia. Or they may have become convinced they are hypoglycemic from listening to a friend who thinks everyone is suffering from this condition.
There are chat rooms full of anxious men and women who feel they are hypoglycemic and who recommend a hypoglycemic diet to everyone else who feels anxious. The conviction some individuals have that they are hypoglycemic can rise to delusional proportions and can persist in the face of any amount of contrary evidence. They discount repeated blood sugar tests in the normal range, despite their being obtained at times when “hypoglycemic” symptoms are present. “I know what I feel, and I can see for myself,” they insist. In an attempt to convince one patient that her blood sugar levels had nothing to do with her symptoms, I tested her blood sugar every time she became symptomatic. When all the tests came back normal, she still believed she had hypoglycemia. I had convinced her, instead, that our laboratory was unreliable.
It is very difficult to help these people overcome their phobias since they attribute their condition not to a mistaken understanding of themselves and of the world but rather to a physiological state. In that case there is nothing to learn from practicing coping in the phobic situation. Yet despite their diet, they still have panic attacks and remain phobic.
True hypoglycemia is complicated and beyond the scope of this blog. Certain salient points should be made, though:
1. The diagnosis of hypoglycemia cannot be made by observing one’s symptoms subjectively and then relating them to diet. It is too easy to be led astray.
2. The five-hour glucose tolerance test was not designed to test for hypoglycemia, and it is not very useful for that purpose. The test is inconsistent from laboratory to laboratory and from time to time, depending in part on what the patient ate during the two or three days prior to the test and on how long the blood is allowed to stand in the test tube. (With time, the sugar level drops falsely by as much as 30 percent.) Finally, the test itself provokes low blood sugar unnaturally by requiring ingestion of pure sugar after a period of prolonged abstinence from food. This is not an ordinary diet.
3. Fifty percent of normal people will run a blood sugar below 70 milligrams per deciliter at times. Healthy men who have been fasting for three days often reach levels in the low 5Os without experiencing symptoms or showing any signs of bodily dysfunction. During the course of a glucose tolerance test, 25 percent of normal people are found to have a level below 50 mgm/dl. If during the tests their level is monitored continuously, 42 percent are below 50 mgm/dl. The level of fasting blood sugar strongly suggestive of hypoglycemia is below 40 mgm/dl, although a higher level between 40 and 60 mgm/dl. is a “gray zone” consistent under certain circumstances with hypoglycemia.
In order to make the diagnosis properly, however, these levels must regularly produce the symptoms described above, and each time when the level of blood sugar is raised, the symptoms should disappear.
4. In fact, the diagnosis of hypoglycemia should be pursued in the first place by repeated determinations of blood sugar levels at those times when the patient is experiencing symptoms. It is these readings that are important, rather than the results of a glucose tolerance test. Tested in such a way, the great majority of phobic patients can quickly reassure themselves that they do not have this additional problem.
5. Finally, when hypoglycemia is present, it is vitally important to discover its cause. There are a number of possible illnesses that precipitate hypoglycemia. Some are serious. Some are curable. All deserve specific treatment beyond staying away from sugar and entering upon a lifetime of eating small and frequent meals.
In summary, if you feel there is reason to think you have hypoglycemia, you should see an appropriate physician and take the appropriate tests and, if necessary, the proper treatment. Someone who is phobic will have to enter into exposure therapy in any case. There is no connection between agoraphobia and hypoglycemia except that the symptoms of one are vaguely suggestive of the other.
Of course, most patients who think they have hypoglycemia have seen a doctor and have been told that they have that condition. It is unfortunately true that many doctors are careless in making such a diagnosis. A particularly egregious misdiagnosis came to my attention when a patient came for treatment literally holding a carrot in one hand and a tranquilizer in the other. She recognized that she was overly anxious, but attributed her problem to hypoglycemia. She was making a point of eating every few hours. Her doctor told her she had this condition and to eat frequently. But when I checked her glucose level, it was over 60 mgm/dl. I called her physician, who happened to have an office near to me.
“Why did you think Mrs._____ has hypoglycemia? I asked him.
“You know, I think there is such a condition as reactive hypoglycemia,” he replied, acknowledging the controversy over its existence.
“Yes, I know. But her blood sugar was over sixty. That isn’t hypoglycemia.”
“All right, what do you want me to do? Send her back to me, and I’ll tell her she doesn’t have it.”
In other words, it didn’t matter much to him one way or the other whether she had hypoglycemia. His casual remark about eating frequently was taken as gospel by the patient though.
If you have been told you have hypoglycemia by a physician, check with an endocrinologist to see if that diagnosis is accurate. If it is, an attempt should be made to find the cause. Excerpted from “Rising Above Fear.” (c) Fredric Neuman
Next: Mitral Valve Prolapse.