What are the muscle cramps? What is the role of low potassium and magnesium in muscle cramp? Read out full article to get detailed info about muscle cramps.
Muscles are mainly of two types: voluntary muscles and involuntary muscles. Muscles of arms and legs can voluntarily be controlled and they contract and relax as the person moves the limbs. When these muscles or some fibers of these muscle involuntarily contracts, this is called a “spasm”. If a spasm is vigorous and continued, it becomes a “cramp”. Thus, a muscle cramp can be described as an involuntarily and forcibly contracted muscle which does not relax. Muscle cramp may be associated to part of a muscle, the entire muscle or a group of muscles. It may happen several times till it goes away. The duration of a muscle cramp varies from few seconds to a quarter of an hour.
Approximately, 95% individuals experience muscle cramps at some time in their life. Though, they are very common in adults and increase with age, they can also be experienced by children. Skeletal muscles come under the voluntary control and they can also cramp. Blood vessel wall, intestinal tract and urine passages are made up of involuntary muscles and they are also susceptible to cramps. Muscle cramps of the legs and feet and particularly the calf are widespread.
Types of muscle cramps:
Muscle cramps can be categorized into four major types as per the causes and muscle groups affected.
“True” cramps:
“True” cramps are the most common types of skeletal muscle cramps which involve part or all of a single muscle or a group of muscles that usually act together, such as the muscles that flex several adjacent fingers. The reason of incidence of “True” cramps is the hyper-excitability of the nerves that stimulate the muscles. Injury, vigorous activity, dehydration, body fluid shifts, low blood calcium and magnesium or low potassium are the other causes of “True” cramps.
Contractures:
Contractures are uncommon and result when the muscles are unable to relax. Adenosine triphosphate (ATP) is energy chemical in the cell that prevents muscle fiber relaxation. In contracture, a depletion of ATP takes place. The nerves remain inactive in this form of muscle spasm. Hereditary contractures are called McArdle’s disease. This is an imperfection of the breakdown of glycogen to sugar in the muscle cell. If the contracture is obtained, it is called hyperthyroid myopathy. This is associated with overactive thyroid.
Tetany:
All the nerve cells in the body are activated in tetany and these stimulate the muscles. This reaction causes spasms or cramps all over the body. Generally, the term tetany is applied to muscle cramps because of conditions like low blood level of calcium and magnesium. Low blood calcium level causes cramps of the hands and the wrists. Numbness and tingling are also experienced around the mouth and some other regions. Sometimes, tetanic cramps are impossible to differentiate from “true” cramps. The supplementary changes of sensation or other nerve functions that happen with tetany may not be obvious because the cramp pain is masking or distracting from it.
Dystonic cramps:
In dystonic cramps, muscles that are not needed for the intended movement are stimulated to contract. Dystonic cramps affects muscles that work in the opposite direction of the intended movement or those that exaggerate the movement. Sometimes small groups of muscles like eyelids, neck, jaws, and larynx are usually affected by such cramps. Dystonic cramps may affect the hands and arms during the performance of repetitive activities such as those associated with handwriting (writer’s cramp), typing, playing certain musical instruments, and many others. Each of these repetitive activities may also create “true” cramps from muscle fatigue.
Aside from these muscle cramps, some other types of muscle cramps are also in existence due to amyotrophic lateral sclerosis, radiculopathy, diabetic neuropathy and primarily dystonic muscle diseases.
Causes of Muscle Cramps:
Hyper-excitably in the nerves stimulates the muscles and then resulted in to muscle cramps. Particularly, this can take place after injury to nerve and/or muscle, dehydration, with low blood levels of calcium, magnesium, or potassium, from certain medications, and even at rest. The pain related with muscle cramps are caused by poor circulation to the legs that worsens with walking. Muscle cramps can also be caused due to deficiencies of certain vitamins, including thiamine (B1), pantothenic acid (B5), and pyridoxine (B6).
Role of Low Potassium in Muscle Cramps:
Muscles and nerves rely on electrolytes to function properly. Purging causes the depletion of potassium level in the body and the potassium deficiency symptoms like spasms and muscle cramps are produced. Muscle weakness, fatigue, depression and irritability are the other symptoms of the potassium deficiency.
Potassium is the major electrolyte which is present inside all body cells, including muscle and nerve cells. In the generation of electrical impulses in the nerves and the muscles, potassium works in close relationship with sodium and chloride. Fresh vegetables, potatoes, certain fruits (melon, bananas, berries, and citrus fruit), milk, meat, and fish are good sources of potassium.
Potassium deficiency can occur with conditions such as fasting, diarrhea, and regular diuretic use. Potassium deficiency is also called as hypokalemia. Hypomagnesemia, magnesium deficiency is another cause of hypokalemia. Both potassium and magnesium deficiencies have an effect on one another and are closely connected.
Role of Low Magnesium in Muscle Cramps:
Mainly an insufficient concentration of magnesium in the blood directly increases the excitability of both the nerve endings and the muscles they stimulate. This may be a predisposing factor for the spontaneous “true” cramps. Cramps are seen in any condition that reduces the availability of calcium or magnesium in body fluids, such as from diuretics, hyperventilation, excessive vomiting, inadequate calcium and/or magnesium in the diet, inadequate calcium absorption due to vitamin D deficiency, poor function of the parathyroid gland, and other conditions.
Magnesium is a vital mineral that taken in the body by the food that people consume. Magnesium deficiency can take place because of low supply or through an intensive excretion of magnesium, such as sweating, which results in a more spontaneous responsiveness of the nerves that are responsible for the contractions of the muscle, especially within calf and thigh muscles. Consume more foods that contain large amounts of magnesium.
Injury:
When injury occurs in the body, persistent muscle spasm may take place as a protective mechanism. Injury of the muscle only may cause the muscle to spasm.
Vigorous activity:
Vigorous use of muscles and muscle fatigue are also related with muscle cramps. These type of muscle cramps may come during the activity or even hours later. Similarly, muscle fatigue from sitting or lying for an extended period in an awkward position, or any repetitive use can cause cramps. During performing vigorous or strenuous physical activities, older adults are more at risk for these types of cramps.
Rest cramps:
During rest, cramps are also very common and can be practiced at any age including childhood. Rest cramps frequently take place during the night. While not life-threatening, night cramps can be painful, disturbing of sleep, and they can recur repeatedly. The real cause of night cramps is unidentified. Sometimes, they are initiated by making a movement that shortens the muscle.
Dehydration:
Excessive fluid loss can take place from perspiration by sports and other vigorous activities. This type of dehydration raises “true” cramps. In warm weather, these cramps are more likely to be happen and can be an early sign of heat stroke. Sodium depletion has also been related with cramps.
Treatment of Muscle Cramp:
- Gently massage the muscle or apply warmth with a hot soak or heating pad
- Fluid and electrolyte (sodium and potassium) replacement
- The muscle has to be stretched. This is done by standing up and walking around.
- For cramps like writer’s cramp, press the hand on a flat surface.
- Injections of therapeutic doses of botulism toxin are used for dystonic muscle disorders.
- In case of a calf muscle cramp, one should stand 2 or 2.5 feet from the wall, lean towards the wall, place the forearms against the wall, keep knees and back straight and heels in contact with the floor or pull the toes upwards towards the head, while lying in bed and keeping the leg straight as possible.
Prevention of Muscle Cramp:
- Avoid excessive fatigue
- Intake of 400 units of vitamin E
- Good hydration and replacement of lost electrolytes of sodium and potassium
- Intake of supplements of calcium, potassium and magnesium
- For rest/night cramps, perform stretching exercises before bed
- Stretching before and after vigorous physical activity accompanied by sufficient warm-up and cool down
- For dystonic cramps, use wrist supports, avoid high heels, adjust chair position, take activity breaks, avoid excessive tension
First-Aid – Muscle Cramps (Video from Youtube):
Muscle Spasms and Cramps Health Byte (Video from Youtube):
