The list of possible diseases that lead to excessive nervousness or even panic attacks is too large to discuss here. I will only highlight a few possibilities, which will help to show the scale of the problem. Most of the diseases described below can NOT be detected by basic general examinations. In other words, the attitude “I had a blood test, nothing came out, I am healthy” is – to put it mildly – wrong. Even a few dozen of basic tests cannot detect the vast majority of such atypical diseases. You need a test for a specific condition to show it.
Both hypothyroidism and hyperthyroidism will cause anxiety (hyperthyroidism much stronger). Many people are treated for diseases of this organ, but the therapy is often carried out incorrectly. If we feel any symptoms and the results are “normal”, we are NOT being treated correctly – it is the patient who is supposed to feel good, not a piece of paper with a printed result. Normal is a very broad area, both results just outside the lower limit and just outside the upper limit can give symptoms. Plus there are 3 different hormones, and doctors often judge a patient’s condition by just one of them.
There are a whole range of nutritional deficiencies that are NOT diagnosable by a simple blood test, or even the more complicated ones (for example, the magnesium level in a test may be good, but the same magnesium inside the cells will be well below normal, and this cannot be tested by a basic test).
Any disease that leads to disturbances in the pH of the body, or latent tetany. Patients with these very often get a diagnosis of neurosis. In one study it turned out that almost every patient with agoraphobia (a specific variety of panic attacks) actually had latent tetany on the background of magnesium deficiency:
https://pubmed.ncbi.nlm.nih.gov/7553952/
All kinds of adrenal disorders (and no, the descriptions on the internet of “adrenal fatigue syndrome” are not true, it’s a hoax). This is not a very common ailment, but every now and then you hear that someone died because they were not properly diagnosed. It is not even so much about neurosis, as a threat to health and life associated with untreated disorders of this type.
Disorders of blood flow in the carotid arteries and any other circulatory disorders. If the blood does not reach the brain, nervousness occurs. Sometimes the cause is as trivial as simply holding the head crookedly, which causes compression. Then all that is needed is appropriate corrective gymnastics.
All kinds of chronic infections and parasitic diseases. As a rule, parasitic infection will be visible in the peripheral blood smear, then there will be strongly increased eosinophils, but firstly, not always, and secondly, not only infections cause changes in the smear.
Disturbed composition of intestinal flora. The famous “candida” is only an Internet myth, but in fact there is a whole group of diseases in which the body is poisoned by the effects of bacterial metabolism, and even their translocation, that is, the passage from the intestines to different regions of the body. As a rule, this situation is secondary to another disease, for example, in cirrhosis of the liver there is a decrease in bile secretion, which allows pathogenic bacteria to multiply.
I repeat, this is not a list of diseases that should be diagnosed when you have panic attacks, but an attempt to highlight the problem, to show that such diseases exist. There are many more, here I am only trying to show the tip of the iceberg.