Numbness in the fingers. Tingling around the mouth. Suddenly, it becomes difficult to take a deep breath. The heart starts beating faster, the hands become stiff, and the fingers involuntarily curl inward. In such moments, many people are convinced they are having a heart attack or a stroke, or that something life-threatening is happening. It is not uncommon for these episodes to result in a visit to the Emergency Department. Only later do they learn that the symptoms may have been caused by tetany or an episode of hyperventilation.
This is why tetany causes so much concern. Its symptoms can be intense while remaining highly nonspecific. Tingling, muscle tremors, palpitations, and shortness of breath may also occur in many other medical conditions. Symptoms alone are usually not enough to establish the diagnosis.
Tetany is not a single disease. It is a syndrome caused by increased excitability of nerves and muscles. Under normal conditions, nerve cells transmit electrical impulses only when necessary. In tetany, the threshold for nerve excitation is lowered, causing muscles to react too easily. As a result, patients may experience tingling, numbness, painful muscle cramps, muscle twitching, and sometimes the characteristic hand spasm known as the “obstetrician’s hand” or carpopedal spasm.
Many people believe that tetany is simply the result of magnesium deficiency. This is one of the most common misconceptions. Magnesium certainly plays an important role in the functioning of the nervous system, but the most critical factor is ionized calcium-the biologically active form of calcium circulating in the bloodstream. Ionized calcium is essential for proper nerve impulse transmission. When its concentration decreases, nerves become excessively excitable and may fire impulses even when they should not.
This does not mean that magnesium can be ignored. Magnesium deficiency may impair the secretion of parathyroid hormone (PTH), which regulates calcium balance. Consequently, magnesium supplementation can indeed improve symptoms in some patients. However, it is not a universal solution for everyone experiencing tingling in the hands or muscle cramps.
Few people realize that the serum magnesium level does not always reflect the body’s total magnesium stores. Approximately 99% of magnesium is located inside cells and in bones, while only a small fraction circulates in the bloodstream. Therefore, a normal blood magnesium level does not necessarily exclude magnesium deficiency. At the same time, it does not mean that everyone with a normal laboratory result should take magnesium supplements “just in case.”
Symptoms of tetany frequently appear during periods of intense stress. This is not because stress itself causes tetany, but because many people begin to breathe too rapidly and too deeply. Such hyperventilation lowers the level of carbon dioxide in the blood, which temporarily reduces the concentration of ionized calcium. As a result, patients may develop tingling around the mouth, numbness in the fingers, stiffness of the hands, dizziness, and painful muscle cramps. This explains why a panic attack and tetany can appear almost identical.
In clinical practice, physicians often encounter patients who have been treating themselves for a “magnesium deficiency” for months simply because they read online that magnesium deficiency explains all of their symptoms. In reality, similar complaints may also occur in vitamin B12 deficiency, thyroid disorders, diabetes, peripheral neuropathies, electrolyte disturbances, parathyroid diseases, carpal tunnel syndrome, or even chronic muscle tension affecting the neck and shoulders. This is why self-diagnosis frequently leads to incorrect conclusions.
When tetany is suspected, a physician may order laboratory tests including total calcium, ionized calcium, magnesium, potassium, phosphate, vitamin D, and parathyroid hormone (PTH). In selected cases, an electromyographic ischemic test (EMG tetany test) may also be performed. However, this investigation is not necessary for every patient experiencing numbness of the hands or face. The decision depends on the clinical presentation and the results of the initial diagnostic evaluation.
Treatment depends entirely on the underlying cause. Some patients require correction of calcium-phosphate metabolism disorders, others benefit from vitamin D or magnesium supplementation, while some need treatment for anxiety disorders together with breathing retraining. There is no single medication that effectively treats every case of tetany.
The greatest mistake is relying solely on information found online. Tingling in the hands, facial numbness, or muscle cramps are symptoms that can occur in many different medical conditions. Sometimes they are indeed caused by tetany, but just as often they have an entirely different origin. The most important step is therefore not assigning a name to the condition but determining why these symptoms have developed in a particular individual. Only identifying the true underlying cause makes it possible to implement treatment that is genuinely effective.
Patient FAQ
Is tetany life-threatening?
Tetany itself is usually not life-threatening. However, its symptoms can closely resemble serious medical emergencies such as a heart attack or stroke, which require immediate medical evaluation.
Can tetany be diagnosed with blood tests?
Not always. Routine laboratory tests may be normal, so their interpretation should always take into account the patient’s symptoms and the results of additional diagnostic investigations.
Does alcohol affect tetany?
Yes. Excessive alcohol consumption can lead to electrolyte disturbances and increase the risk of developing tetany symptoms.
Is tetany more common in women than in men?
Yes. Tetany is diagnosed more frequently in women, particularly in young adults. However, it remains unclear whether this reflects a genuinely higher prevalence or whether women are simply more likely to seek medical attention for these symptoms.
Can tetany be caused by thyroid disease?
Indirectly, yes. Certain disorders of the thyroid gland and, particularly, the parathyroid glands can disrupt calcium metabolism and contribute to the development of tetany symptoms.
