Muscle Cramps

Muscle cramps feeling is a common problem. Muscle cramps may be quite banal, but sometimes they belong to manifestations of some serious diseases. A muscle cramp is an unpleasantly perceived involuntary muscle contraction. It is important to distinguish muscle cramps of certain muscle groups and convulsions affecting most or all muscles in the body.


It is virtually impossible to name all possible causes of muscle cramps so I try to include at least the most common and the most important.

Muscle fatigue after physical exertion

This is probably the most usual cause of pain and spasms of certain muscle groups. It occurs regularly among untrained individuals who undergo too intensive physical exertion. Pain and muscle cramps after such load are obviously harmless.

Magnesium deficiency

This is a relatively common cause of muscle spasms of the lower extremities. Spasms tend to be uncomfortable, but they are usually not strong. Magnesium deficiency can be determined from blood samples and problem disappears after administering magnesium supplements.

Venous disorders

This group of diseases can manifest with feeling of heavy legs, leg pain and muscle cramps. More information can be found in relevant article.


Hyperventilation (deep and rapid breathing) is a simple way to cause oneself muscle cramps. It is typical especially for hysterical women. During hyperventilation there is a drop in carbon dioxide blood level (this gas is breathed out) and that leads to decrease of free calcium concentration in the blood. Calcium is very important for proper muscle function and its relative deficiency (hypocalcemia) causes tingling sensations in extremities followed by muscle cramps. Best therapy is to calm down the affected person to stop hyperventilation. If needed, tranquilizer drugs can be used.

Elevated temperature

Fever is a common cause of seizures in children when we talk about the so-called febrile seizures. It is nothing unusual and treating fever with non-steroidal anti-inflammatory drugs solves the problem.


Hypoglycemia means decreased concentration of blood sugar (glucose). Dangerous hypoglycemia may occur in patients with diabetes who are treated with insulin or oral hypoglycemic agents. This medication lowers blood sugar and in overdose it can easily cause hypoglycemic condition. Severe hypoglycemia manifests with muscle cramps, convulsions and loss of consciousness. Quick sugar administration in form of sweetened fluid or intravenous glucose is the best treatment.


Some forms of epileptic seizures manifest by muscle cramps and convulsions. These may be involuntary spasms of certain muscle groups or global convulsions associated with fall and unconsciousness. More detailed description including prevention, first aid and treatment can be found in texts dedicated to epilepsy and status epilepticus.

Brain infections

Brain infections such as meningitis and infection of brain tissue (encephalitis) can have a variety of symptoms including muscle cramps and seizures. The patient usually has stiff neck, vomits and fever is present. Spinal tap is an appropriate examination; cerebrospinal fluid sample can inform us about many pathological conditions.

Brain tumors

Brain tumors can cause epileptic seizures and muscle cramps. It is rather the effect of benign tumors that oppress and irritate surrounding brain tissue, but it may be also present in malignant brain tumors.

Hemorrhagic stroke

Stroke developed secondary to brain bleeding can cause muscle cramps and convulsions in addition to paralysis and speech disorders. Ischemic stroke arising from a blockage of brain arteries is not so often accompanied by cramps.

Toxic compounds

Intoxication with many addictive substances including alcohol and other drugs (cocaine, amphetamines, etc.) may lead to convulsions and it is the same with withdrawal symptoms.

Overactive thyroid gland

Overactive thyroid gland can cause life-threatening condition associated with loss of consciousness, hand tremor, and muscle convulsions. This condition is referred to as thyrotoxic crisis (also called thyroid storm). Thyrotoxic crisis occurs because of inadequately strong effect of thyroid hormones.


This is a serious state occurring in pregnant women that can cause death of both the mother and her child. That is why every condition accompanied with cramps must be considered as potentially dangerous in pregnant women. Eclampsia is usually preceded by a condition known as preeclampsia that manifests by high blood pressure and protein in urine.


This is a dangerous infectious disease caused by bacterium Clostridium tetani. Toxin produced by the bacteria attacks the nerve endings in the muscles and causes severe cramps and stiffness of the majority of muscles including respiratory muscles. Untreated condition usually ends by unpleasant death by suffocation. Such terrible consequences are luckily rare in developed countries thanks to vaccination.

Diagnostic approach

Diagnosis of muscle cramps can be very challenging. Medical history and physical examination should be as always the first part of medical check-up. Lots of information can be ascertained from blood samples (concentration of minerals, blood sugar level, inner environment, thyroid hormones, etc). Especially in children, body temperature shall be measured to rule out febrile cramps. When brain affection is suspicious, it is advisable to perform computed tomography or magnetic resonance imaging followed by neurological examination including electroencephalography. Especially in cases of suspected brain infection doctors usually execute spinal tap to obtain sample of cerebrospinal fluid.


If necessary, we treat the underlying cause of muscle cramps. Convulsions alone are solved by administration of anticonvulsants and muscle relaxants.

Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources