Cramp | |
---|---|
Symptoms | sudden muscle pain and a paralysis-like immobility |
Treatment | quinine, stretching, massage, and drinking liquids |
A cramp is a sudden, involuntary, painful skeletal muscle contraction [1] [2] or overshortening associated with electrical activity; [3] while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the affected muscle. A cramp usually goes away on its own over a period of several seconds or (sometimes) minutes. [4] Cramps are common and tend to occur at rest, usually at night (nocturnal leg cramps). [2] [5] They are also often associated with pregnancy, physical exercise or overexertion, and age (common in older adults); in such cases, cramps are called idiopathic, because there is no underlying pathology. In addition to those benign conditions cramps are also associated with many pathological conditions. [2] [6]
Cramp definition is narrower than the definition of muscle spasm: spasms include any involuntary abnormal muscle contractions, while cramps are sustained and painful. [1] [7] True cramps can be distinguished from other cramp-like conditions. Cramps are different from muscle contracture, which is also painful and involuntary, but which is electrically silent. The main distinguishing features of cramps from dystonia are suddenness with acute onset of pain, involvement of only one muscle and spontaneous resolution of cramps or their resolution after stretching the affected muscle. [2] Restless leg syndrome is not considered the same as muscle cramps and should not be confused with rest cramps. [6]
Skeletal muscle cramps may be caused by muscle fatigue or a lack of electrolytes [ citation needed ] such as sodium (a condition called hyponatremia), potassium (called hypokalemia), or magnesium (called hypomagnesemia [8] ). Some skeletal muscle cramps do not have a known cause. [6] Motor neuron disorders (e.g., amyotrophic lateral sclerosis), metabolic disorders (e.g., liver failure), some medications (e.g., diuretics and inhaled beta‐agonists), and haemodialysis may also cause muscle cramps. [6]
Causes of cramping include [9] hyperflexion, hypoxia, exposure to large changes in temperature, dehydration, or low blood salt. Muscle cramps can also be a symptom or complication of pregnancy; kidney disease; thyroid disease; hypokalemia, hypomagnesemia, or hypocalcaemia (as conditions); restless legs syndrome; varicose veins; [10] and multiple sclerosis. [11]
As early as 1965, researchers observed that leg cramps and restless legs syndrome can result from excess insulin, sometimes called hyperinsulinemia. [12]
Under normal circumstances, skeletal muscles can be voluntarily controlled. Skeletal muscles that cramp the most often are the calves, thighs, and arches of the foot, and in North America are sometimes called a "Charley horse" or a "corky". Such cramping is associated with strenuous physical activity and can be intensely painful; however, they can even occur while inactive and relaxed. Around 40% of people who experience skeletal cramps are likely to endure extreme muscle pain, and may be unable to use the entire limb that contains the "locked-up" muscle group. It may take up to a week for the muscle to return to a pain-free state, depending on the person's fitness level, age, and several other factors.[ citation needed ]
Nocturnal leg cramps are involuntary muscle contractions that occur in the calves, soles of the feet, or other muscles in the body during the night or (less commonly) while resting. The duration of nocturnal leg cramps is variable, with cramps lasting anywhere from a few seconds to several minutes. Muscle soreness may remain after the cramp itself ends. These cramps are more common in older people. [13] They happen quite frequently in teenagers and in some people while exercising at night. Besides being painful, a nocturnal leg cramp can cause much distress and anxiety. [14] The precise cause of these cramps is unclear. Potential contributing factors include dehydration, low levels of certain minerals (magnesium, potassium, calcium, and sodium, although the evidence has been mixed), [15] [16] [17] and reduced blood flow through muscles attendant in prolonged sitting or lying down. Nocturnal leg cramps (almost exclusively calf cramps) are considered "normal" during the late stages of pregnancy. [18] They can, however, vary in intensity from mild to extremely painful.[ citation needed ]
A lactic acid buildup around muscles can trigger cramps; however, they happen during anaerobic respiration when a person is exercising or engaging in an activity where the heartbeat rises. Medical conditions associated with leg cramps are cardiovascular disease, hemodialysis, cirrhosis, pregnancy, and lumbar canal stenosis. Differential diagnoses include restless legs syndrome, claudication, myositis, and peripheral neuropathy. All of them can be differentiated through careful history and physical examination. [17]
Gentle stretching and massage, putting some pressure on the affected leg by walking or standing, or taking a warm bath or shower may help to end the cramp. [19] If the cramp is in the calf muscle, dorsiflexing the foot (lifting the toes back toward the shins) will stretch the muscle and provide almost immediate relief. There is limited evidence supporting the use of magnesium, calcium channel blockers, carisoprodol, and vitamin B12. [17]
Quinine is no longer recommended for treatment of nocturnal leg cramps due to potential fatal hypersensitivity reactions and thrombocytopenia. Arrhythmias, cinchonism, and hemolytic uremic syndrome can also occur at higher dosages. [17]
Various medications may cause nocturnal leg cramps: [17] [20]
Statins may sometimes cause myalgia and cramps among other possible side effects. Raloxifene (Evista) is a medication associated with a high incidence of leg cramps. Additional factors, which increase the probability for these side effects, are physical exercise, age, history of cramps, and hypothyroidism. Up to 80% of athletes using statins experience significant adverse muscular effects, including cramps; [21] the rate appears to be approximately 10–25% in a typical statin-using population. [22] [23] In some cases, adverse effects disappear after switching to a different statin; however, they should not be ignored if they persist, as they can, in rare cases, develop into more serious problems. Coenzyme Q10 supplementation can be helpful to avoid some statin-related adverse effects, but currently there is not enough evidence to prove the effectiveness in avoiding myopathy or myalgia. [24]
Stretching, massage, and drinking plenty of liquids may be helpful in treating simple muscle cramps. [25]
The antimalarial drug quinine is a traditional treatment that may be slightly effective for reducing the number of cramps, the intensity of cramps, and the number of days a person experiences cramps. Quinine has not been shown to reduce the duration (length) of a muscle cramp. [6] Quinine treatment may lead to haematologic and cardiac toxicity. Due to its low effectiveness and negative side effects, its use as a medication for treating muscle cramps is not recommended by the FDA. [26]
Magnesium is commonly used to treat muscle cramps. Moderate quality evidence indicates that magnesium is not effective for treating or preventing cramps in older adults. [6] It is not known if magnesium helps cramps due to pregnancy, liver cirrhosis, other medical conditions, or exercising. [6] Oral magnesium treatment does not appear to have significant major side effects, however, it may be associated with diarrhea and nausea in 11–37% of people who use this medicine. [6]
With exertional heat cramps due to electrolyte abnormalities (primarily potassium loss and not calcium, magnesium, and sodium), appropriate fluids and sufficient potassium improves symptoms. [27] Vitamin B complex, naftidrofuryl, lidocaine, and calcium channel blockers may be effective for muscle cramps. [26]
Adequate conditioning, stretching, mental preparation, hydration, and electrolyte balance are likely helpful in preventing muscle cramps. [25]
Benign fasciculation syndrome (BFS) is characterized by fasciculation (twitching) of voluntary muscles in the body. The twitching can occur in any voluntary muscle group but is most common in the eyelids, arms, hands, fingers, legs, and feet. The tongue can also be affected. The twitching may be occasional to continuous. BFS must be distinguished from other conditions that include muscle twitches.
Alkalosis is the result of a process reducing hydrogen ion concentration of arterial blood plasma (alkalemia). In contrast to acidemia, alkalemia occurs when the serum pH is higher than normal. Alkalosis is usually divided into the categories of respiratory alkalosis and metabolic alkalosis or a combined respiratory/metabolic alkalosis.
Writer's cramp or focal hand dystonia (FHD) is an idiopathic movement disorder of adult onset, characterized by abnormal posturing and movement of the hand and/or forearm during tasks requiring skilled hand use, such as writing. Overcontraction of affected muscles, cocontraction of agonist and antagonist pairs, and activation of muscles inappropriate to a task all impair use of the affected hand.
Heat exhaustion is a heat-related illness characterized by the body's inability to effectively cool itself, typically occurring in high ambient temperatures or during intense physical exertion. In heat exhaustion, core body temperature ranges from 37 °C to 40 °C. Symptoms include profuse sweating, weakness, dizziness, headache, nausea, and lowered blood pressure, resulting from dehydration and serum electrolyte depletion. Heat-related illnesses lie on a spectrum of severity, where heat exhaustion is considered less severe than heat stroke but more severe than heat cramps and heat syncope.
Muscle fatigue is when muscles that were initially generating a normal amount of force, then experience a declining ability to generate force. It can be a result of vigorous exercise, but abnormal fatigue may be caused by barriers to or interference with the different stages of muscle contraction. There are two main causes of muscle fatigue: the limitations of a nerve’s ability to generate a sustained signal ; and the reduced ability of the muscle fiber to contract.
Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte. Examples of electrolytes include calcium, chloride, magnesium, phosphate, potassium, and sodium.
Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abnormal heart rhythm, which is often too slow and can cause cardiac arrest.
"A charley horse" is an American term for a very painful involuntary cramp in the legs and/or foot, lasting anywhere from a few seconds to a couple days. The phrase formerly referred more commonly to bruising of the quadriceps muscle of the anterior or lateral thigh, or contusion of the femur, that commonly results in a haematoma and sometimes several weeks of pain and disability. In this latter sense, such an injury is known as dead leg.
Gitelman syndrome (GS) is an autosomal recessive kidney tubule disorder characterized by low blood levels of potassium and magnesium, decreased excretion of calcium in the urine, and elevated blood pH. It is the most frequent hereditary salt-losing tubulopathy. Gitelman syndrome is caused by disease-causing variants on both alleles of the SLC12A3 gene. The SLC12A3 gene encodes the thiazide-sensitive sodium-chloride cotransporter, which can be found in the distal convoluted tubule of the kidney.
Diving disorders, or diving related medical conditions, are conditions associated with underwater diving, and include both conditions unique to underwater diving, and those that also occur during other activities. This second group further divides conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure, and a range of conditions caused by general environment and equipment associated with diving activities.
Myotonia congenita is a congenital neuromuscular channelopathy that affects skeletal muscles. It is a genetic disorder. The hallmark of the disease is the failure of initiated contraction to terminate, often referred to as delayed relaxation of the muscles (myotonia) and rigidity. Symptoms include delayed relaxation of the muscles after voluntary contraction (myotonia), and may also include stiffness, hypertrophy (enlargement), transient weakness in some forms of the disorder, severe masseter spasm, and cramping. The condition is sometimes referred to as fainting goat syndrome, as it is responsible for the eponymous 'fainting' seen in fainting goats when presented with a sudden stimulus. Of note, myotonia congenita has no association with malignant hyperthermia (MH).
Magnesium deficiency is an electrolyte disturbance in which there is a low level of magnesium in the body. Symptoms include tremor, poor coordination, muscle spasms, loss of appetite, personality changes, and nystagmus. Complications may include seizures or cardiac arrest such as from torsade de pointes. Those with low magnesium often have low potassium.
Acute muscle soreness (AMS) is the pain felt in muscles during and immediately, up to 24 hours, after strenuous physical exercise. The pain appears within a minute of contracting the muscle and it will disappear within two or three minutes or up to several hours after relaxing it.
Tetany or tetanic seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disorders that increase the action potential frequency of muscle cells or of the nerves that innervate them.
Heat cramps, a type of heat illness, are muscle spasms that result from loss of large amount of salt and water through exercise. Heat cramps are associated with cramping in the abdomen, arms and calves. This can be caused by inadequate consumption of fluids or electrolytes. Heavy sweating causes heat cramps, especially when the water is replaced without also replacing salt or potassium.
Heat illness is a spectrum of disorders due to increased body temperature. It can be caused by either environmental conditions or by exertion. It includes minor conditions such as heat cramps, heat syncope, and heat exhaustion as well as the more severe condition known as heat stroke. It can affect any or all anatomical systems. Heat illnesses include: heat stroke, heat exhaustion, heat syncope, heat edema, heat cramps, heat rash, heat tetany.
Acquired non-inflammatory myopathy (ANIM) is a neuromuscular disorder primarily affecting skeletal muscle, most commonly in the limbs of humans, resulting in a weakness or dysfunction in the muscle. A myopathy refers to a problem or abnormality with the myofibrils, which compose muscle tissue. In general, non-inflammatory myopathies are a grouping of muscular diseases not induced by an autoimmune-mediated inflammatory pathway. These muscular diseases usually arise from a pathology within the muscle tissue itself rather than the nerves innervating that tissue. ANIM has a wide spectrum of causes which include drugs and toxins, nutritional imbalances, acquired metabolic dysfunctions such as an acquired defect in protein structure, and infections.
Exercise-associated muscle cramps (EAMC) are defined as cramping during or immediately following exercise. Muscle cramps during exercise are very common, even in elite athletes. EAMC are a common condition that occurs during or after exercise, often during endurance events such as a triathlon or marathon. Although EAMC are extremely common among athletes, the cause is still not fully understood because muscle cramping can occur as a result of many underlying conditions. Elite athletes experience cramping due to paces at higher intensities. The cause of exercise-associated muscle cramps is hypothesized to be due to altered neuromuscular control, dehydration, or electrolyte depletion.
QT prolongation is a measure of delayed ventricular repolarisation, which means the heart muscle takes longer than normal to recharge between beats. It is an electrical disturbance which can be seen on an electrocardiogram (ECG). Excessive QT prolongation can trigger tachycardias such as torsades de pointes (TdP). QT prolongation is an established side effect of antiarrhythmics, but can also be caused by a wide range of non-cardiac medicines, including antibiotics, antidepressants, antihistamines, opioids, and complementary medicines. On an ECG, the QT interval represents the summation of action potentials in cardiac muscle cells, which can be caused by an increase in inward current through sodium or calcium channels, or a decrease in outward current through potassium channels. By binding to and inhibiting the “rapid” delayed rectifier potassium current protein, certain drugs are able to decrease the outward flow of potassium ions and extend the length of phase 3 myocardial repolarization, resulting in QT prolongation.
Signs and symptoms of pregnancy are common, benign conditions that result from the changes to the body that occur during pregnancy. Signs and symptoms of pregnancy typically change as pregnancy progresses, although several symptoms may be present throughout. Depending on severity, common symptoms in pregnancy can develop into complications. Pregnancy symptoms may be categorized based on trimester as well as region of the body affected.
Hypomagnesemia is an electrolyte disturbance caused when there is a low level of serum magnesium [...] in the blood