Muscle Cramps

Have you ever woken up in the night to an excruciating muscle spasm in your quadriceps, calf or hamstring? You flex and point the leg and knee joint hoping that relief will take hold. Muscles cramps and spasms typically come on as a strong involuntary painful contraction of one or more muscles and lasts from a few seconds to several minutes. Sometimes the residual soreness brought about the muscle cramp can last for hours after episode has stopped. These spasms can be caused by anything that interferes with the mechanisms that cause the muscle to contract or relax. The cause of muscle cramps is not really known. What is know is that muscle cramps may be brought on by many conditions or activities, such as: Long periods of exercise or physical labor, injury, and overuse of muscles as well as other factors such as dehydration. When the muscle goes into a spasm your brain sends a message along the nerves that leads to that muscle triggering a sequence of events controlled by the electric flow of minerals inside and outside of the muscle’s cell membrane causing the muscle to contract. These minerals that exist on opposite sides of the cell’s membrane carries one or more electrical charge. When the message from your brain reaches the muscle, it signals calcium to move into the muscle cells and potassium to move out of the cells. This in and out movement of minerals within the cell sends an electrical current to flow along the muscle causing the intense cramp you get. Once the cell reaches a point of balance the muscle then relaxes. 

The question is how do you keep those muscle cells in a state of balance or homeostasis? For a muscle to contract and relax normally, there needs to be:

An ample quantity of fat and sugar to serve as energy sources.

Arteries large enough to supply the body with oxygen to assist in the utilization of

“Macro” nutrients (Protein-Carbohydrates-Fat).

The right mix and concentration of minerals inside and outside of the cell walls of the muscle.

Whether the cramp occurs starting exercise, after exercise, during activities or when sleeping the treatment is basically the same while prevention varies.

Cramps that begin when you start exercise are usually due to:

A deficiency or excess in the minerals calcium, sodium, or potassium. The blood level imbalance of these minerals allows the muscle to contract yet prevents relaxation.

Low thyroid function or the inability of the muscle to process carbohydrates (sugar).

Abnormal blood mineral levels as a result of low potassium levels caused by vomiting, diuretics, steroids or licorice, diarrhea, or the body’s inability to absorb or retain potassium.

Low salt (sodium) levels in the bloodstream.

Cramps that begin during exercise are usually due to:

Inadequate blood-supply to the muscle. Abnormal mineral levels or diseases that interfere with the body’s ability to utilize food as energy.

Cramps that begin after having exercises a long time:Dehydration compounded by reduced blood volume which interrupts the transport of oxygen to all the exercising muscles.

Cramps that happen when sleeping:

Night cramps increase with age and occur for no known reason. 


Prolonged sitting

Not getting enough potassium, calcium or magnesium in your diet

Certain medication, diuretics, beta blockers and other blood pressure medication

Underlying metabolic conditions

Pinched nerve or special muscle-tendon reflex.

Exaggeration of a normal reflex.

Cramps that happen during exercise or at rest.

Due to a deficiency or excess in the minerals calcium, sodium, or potassium.

Low thyroid function.

Pinched nerve or special muscle-tendon reflex

Inadequate blood supply to the muscle

Exaggeration of a normal reflex.

Relieving the Pain Associated with Cramps:

Massage and stretch muscles

Apply an ice pack, warm towel or heating pad or take a hot bath or shower

Preventing Cramps:

Stay hydrated – Drink water and other liquids throughout the day. Hydration helps the muscle to slide through the contraction phase and relax phase of each movement with more ease.

Stretch after activity, formal exercise, or before you good to bed.

Go to bed wearing loose fitted clothing and assure your bed sheets and blankets are untucked.


Although the specific nature of cramping is unknown, it can be normally attributed to dehydration, electrolyte imbalance, or prolonged muscle fatigue. Acute cramps are best treated with ice, pressure, and slow stretches of the affected muscle to help it relax.


PDR health, What Causes Muscle Cramps, September 22, 2014.

Mona Shangold, M.D., Gabe Mirkin, M.D., The Complete Sports Medicine Book for Women, page 229, 1992., January 2012.

Marcia K. Anderson, Susan J. Hall, Sports Injury Management, Williams & Wilkins, A Waverly Company 1995.