Tetany: The silent disruptor of the balance of body and mind
Neuro(b)log for Patients
You are a patient who has just returned from the hospital emergency department. Your medical report lists a diagnosis of tetany. They say it is not serious. For some people, this state of increased neuromuscular excitability is a silent disruptor of balance—not only of the body but above all of the mind. You are worried. As a neurologist I have seen many patients "affected" by tetany. They have also formed part of the group brought in by ambulance to the emergency department under the "guise" of epilepsy, seizures of unclear cause, hysteria, polyneuropathy, stroke, etc. Acute symptoms of tetany often occur even in otherwise healthy athletes after intense physical exertion, or in gym visitors whose attendance is sporadic and who "give it their all" during a session and may even support it with an energy drink. It can also follow a sleepless night and alcohol consumption, which cause dehydration and mineral imbalance.
Alternative names and scope
Synonyms for this diagnosis include tetanic syndrome, spasmophilia, neurasthenia, autonomic lability or autonomic dystonia, neurocirculatory asthenia, anxious neurosis, latent/cryptogenic/chronic or normocalcemic tetany, and spasmophilic neuropathy.
In this article I will use the term tetany. It encompasses a range of symptoms that subjectively make life unpleasant for the patient (and sometimes for those around them). It provokes anxiety and health‑related fears. Often it leads patients to search the internet for other diagnoses (usually incurable or fatal), which traps them in a vicious circle of anxiety, doubt and fear.
Tetany may present as an acute tetanic attack or as long‑term, various nonspecific symptoms (latent tetany).
Clinical presentation
An acute tetanic attack typically features characteristic cramps of the upper limb, preferentially affecting the elbow, wrist and fingers (the so‑called obstetric hand), or the knee and ankle region (so‑called carpopedal spasms). Essentially the limb is "twisted" by the cramp. An acute tetanic attack is a manifestation of overt tetany.
By contrast, latent tetany does not present with limb cramps but with cramps around the mouth (the so‑called "fish mouth") or of the masticatory muscles, leading to speech or chewing difficulties. More commonly we encounter cramps in the calves, especially at night.
Other symptoms accompanying tetany include depression, anxiety up to phobias, headache, nonspecific dizziness, neck pain from increased muscle tension, and hypersensitivity to noise. Very frequent complaints reported by patients are tingling of the limbs (unilateral or bilateral), a sensation of tightness in the throat ("lump in the throat" or globus hystericus), and swallowing difficulties. Patients often consult not only a neurologist but also a cardiologist or internist because they experience chest pressure unrelated to exertion, palpitations and a sensation of irregular heartbeat, shortness of breath and dry mouth. Other nonspecific symptoms include excessive fatigue, exhaustion or even loss of energy.
Hyperventilatory tetany
Let us look more closely at hyperventilatory tetany.
This condition occurs during hyperventilation and the resulting hypocapnia. Hyperventilation triggered by a stressor (a situation, strong emotion, etc.) can start with a feeling of breathlessness and lead the patient to breathe faster. Hyperventilation means you breathe more rapidly and sometimes more deeply, causing a reduction of carbon dioxide (CO₂) in the blood (hypocapnia). Heart rate increases, and you may feel short of breath or experience chest tightness. Blood vessels (including those supplying the brain) constrict, producing dizziness, tingling and limb cramps, or a fainting sensation accompanied by anxiety, panic and fear of dying.
Causes of tetany
The most common cause of increased neuromuscular excitability is magnesium deficiency (hypomagnesemia). Magnesium is an important cation for modulating the permeability of voltage‑gated calcium channels in cells. It stabilizes membrane potential and blocks excessive neurotransmitter release. Some patients who develop tetany after thyroid surgery may benefit from magnesium treatment.
Low blood magnesium can be caused by certain medications, including diuretics (which can also cause potassium deficiency), cardiac glycosides, laxatives, sulfonamides, chronic corticosteroid use, proton pump inhibitors, fasting and restrictive diets. Release of stress hormones (catecholamines) causes a short‑term drop in blood magnesium and its shift into cells; chronic stress increases urinary magnesium excretion. Diarrhea, vomiting, various gastrointestinal diseases and chronic alcohol use also contribute.
Magnesium deficiency may be associated with tension‑type headache and migraine, anxiety, internal tremor or shaking, and insomnia — not only tetany.
Currently popular on the market are various magnesium preparations with differing forms and bioavailability; I will address this topic in my next article.
Less commonly, low levels of potassium (hypokalemia) and chloride (hypochloremia) can occur. In hypocalcemic tetany the patient shows irritability and impaired concentration. Blood tests may reveal a decrease in the ionized (free) form of calcium (hypocalcemia) even when total serum calcium is normal. This is seen in patients with parathyroid disease (hypoparathyroidism) or vitamin D deficiency. A case has been reported of a young patient after thyroid surgery with severe hypocalcemia presenting with chest pain and priapism (painful, prolonged erection) that resolved after calcium administration — an anecdotal rather than common manifestation of tetany.
How to break the vicious circle
If you have been diagnosed with tetany under any of the terms listed above, you are probably wondering how to get rid of it. Sometimes this is complicated. Tetany can accompany demanding life periods with increased stress load (even if the person is not fully aware of it). It can accompany panic attacks and depression in predisposed individuals. Latent tetany may cause difficulty falling asleep and poor sleep quality. There is no universal cure or single recipe.
Supplementation with minerals helps, especially when deficiencies are present. Magnesium, calcium and vitamin D help stabilize the nervous system. Lifestyle changes are equally important. While it is impossible to avoid stress entirely, one can learn to manage it. Physical activity, especially outdoors, various relaxation techniques (breathing exercises, meditation, yoga, mindfulness), sufficient sleep and a nutrient‑rich diet high in minerals all help.
Various mineral and herbal products are available in pharmacies. I recommend consulting a pharmacist to ensure a herbal preparation will not interact with medications you are taking. Do acute tetanic attacks recur or worsen? Are the cramps severe, do you experience dizziness or loss of consciousness? Do you suspect mineral deficiency or hormonal disorders? These are problems for which you should definitely see a doctor. In some cases physicians use anxiolytics (anti‑anxiety medications) or antidepressants. Seeking psychotherapeutic help is by no means shameful.
I hope this article provided the information you were looking for.
Next time we will discuss stress and its impact on immunity and autoimmune disease.
MUDr. Petra Mištríková, MBA
References for further study:
Steidl L., Tetanický syndrom v interní praxi, jeho obsah, diagnóza a léčba z hlediska metabolizmu magnezia; Interní Med. 2002; 4(3): 113-118
Schrauzer GN. Effect of Stress on Serum and Erythrocyte Magnesium. Magnesium Research, 1995. Whang R et al. Serum and urinary magnesium responses to epinephrine infusion in humans. Am J Physiol, 1984.
Touyz RM. Role of the sympathetic nervous system in magnesium homeostasis. Magnesium Research, 2006.
Turk C, Stollberger C, Huber J, Sehnal E, Finsterer J. Priapism as a manifestation of tetania. Scand J Urol Nephrol. 2009;43(1):94-5. doi: 10.1080/00365590802502368. PMID: 18991191.