Does dehydration cause muscle cramps?

Medical News Today

01-07-2025

Dehydration may be one cause of muscle cramps, and some evidence suggests that electrolyte imbalances also contribute to them.Muscle cramps are painful, involuntary contractions of the muscles that cause them to suddenly tighten. They are temporary, and stretching the affected muscle usually helps relieve them.Researchers are still not clear about the exact cause of muscle cramps, but dehydration and electrolyte imbalances may play a role.This article looks at dehydration and muscle cramps, other possible causes and risk factors, and how to manage and prevent them.How does dehydration cause muscle cramps?According to the American Academy of Orthopaedic Surgeons (AAOS), exercising in hot weather can increase the risk of muscle cramps. This is because the body loses fluids, salt, and electrolytes in sweat. The loss of these substances may cause the muscles to spasm and cramp.According to a 2019 article, there is inconclusive evidence on whether dehydration causes muscle cramps, but changes in water and salt balance may cause them.Heavy sweating, intense exercise, or exercising in hot weather may cause dehydration if people lose more water than they take in.Dehydration can lead to an electrolyte imbalance, which occurs if electrolyte levels in the body are too high or too low. Electrolytes are minerals such as potassium, calcium, and magnesium that support many important processes in the body.Drinking large quantities of plain water without replacing electrolytes may also cause muscle cramps, although there is not enough conclusive evidence to confirm this.What else can cause muscle cramps?Researchers do not know the exact cause of muscle cramps, but the following factors may play a role:muscle fatigue and inadequate stretching, which may cause abnormalities in certain processes that control muscle contractionpoor conditioning, which includes strength and flexibilityRegular stretching helps lengthen muscle fibers, allowing them to function better when exercising. The spinal cord produces automatic reflexes, including muscle responses. Poor conditioning can increase the likelihood of muscle fatigue and affect automatic reflexes.Overexertion reduces the amount of oxygen to a muscle, which can cause waste products to build up and cause a muscle spasm. As the cramp starts, spinal cord reflexes stimulate the muscle to continue contracting.A 2022 study of 98 marathon runners found that runners who experienced muscle cramps did not show greater levels of dehydration or electrolyte loss after the marathon, but had significantly higher biomarkers of muscle damage than those without cramps.The study suggests that muscle damage may contribute to muscle cramps and that strength training may have protective effects.How to manage dehydration crampsWays to help manage dehydration cramps include:stopping the activity that triggered the muscle crampmassaging and stretching the affected muscle, keeping it in the outstretched position until the cramping stopsapplying a warm compress to tight musclesrehydrating and maintaining hydrationafter exercise, replenishing electrolytes as necessary through consuming sports drinks, cow's milk, foods such as bananas, yogurt, lentils, and spinach, or an oral rehydration solution»More on this:How to treat and prevent leg muscle crampsHow to prevent crampsImproving overall fitness and conditioning may help prevent muscle cramps. People can increase their flexibility through regular stretching, particularly before and after exercise.Ways to prevent muscle cramps include:stretching out the muscle groups most prone to cramping, such as calf, hamstring, and quadricep stretchesavoiding overexertionstaying hydrated by sipping unsweetened soft drinks regularly, particularly during exercise and in hot weathermaintaining electrolyte balance by consuming foods or drinks with electrolytesRisk factors for muscle crampsRisk factors for muscle cramps include:illness or overweightoverexertioncertain medications, including diuretics, statins, and pseudoephedrine, which is a decongestantPeople who may have an increased risk of muscle cramps include:infants, young children, and people over the age of 65endurance athletesolder adults who carry out strenuous physical activityFrequently asked questionsWhat's the difference between taking electrolytes and plain water for cramp prevention?Drinking plain water may help prevent dehydration cramps, as it helps maintain fluid balance in the body.If someone anticipates sweating a lot, they can ensure they have a source of electrolytes to consume alongside plain water. Drinking too much plain water may cause an electrolyte imbalance. Drinking plain water may help prevent dehydration cramps, as it helps maintain fluid balance in the body.If someone anticipates sweating a lot, they can ensure they have a source of electrolytes to consume alongside plain water. Drinking too much plain water may cause an electrolyte imbalance. How quickly should I hydrate if I feel a cramp coming on?It is best to hydrate as soon as possible if people feel a cramp coming on, as a loss of fluids and electrolytes may contribute to muscle cramps.It is best to hydrate as soon as possible if people feel a cramp coming on, as a loss of fluids and electrolytes may contribute to muscle cramps.Why do I get muscle cramps at night?Nocturnal leg cramps may link to depression or heart problems. Other causes may include: dehydration pregnancy ageing certain medications, such as diuretics muscle overexertion liver diseaseNocturnal leg cramps may link to depression or heart problems. Other causes may include: dehydration pregnancy ageing certain medications, such as diuretics muscle overexertion liver diseaseHow much should I drink during exercise to prevent cramps?This depends on the person, the temperature they are exercising in, how much they sweat, how strenuous the activity is, and the duration of the activity.When exercising in the heat, people can aim to drink 8 to 12 ounces of fluid every 15 minutes. Staying well-hydrated may help prevent cramps.It is important to hydrate before and after exercise too. Avoid drinking more than 1.5 liters of water per hour to prevent low sodium levels. This depends on the person, the temperature they are exercising in, how much they sweat, how strenuous the activity is, and the duration of the activity.When exercising in the heat, people can aim to drink 8 to 12 ounces of fluid every 15 minutes. Staying well-hydrated may help prevent cramps.It is important to hydrate before and after exercise too. Avoid drinking more than 1.5 liters of water per hour to prevent low sodium levels. When to contact a doctorIt is important to contact a doctor if people experience muscle cramps that:are severeoccur frequentlydo not improve with home remedies such as stretchingare not due to an obvious cause, such as dehydration or strenuous exerciseMuscle cramps are generally harmless but may be a sign of a problem relating to:circulationnutritionhormonesmedicationsnervesmetabolismIn some cases, muscle cramps may be a sign of an underlying condition, such as:irritation or compression of the spinal nervesnarrowing of the spinal canalthyroid diseasechronic infectionhardening of the arteriesliver cirrhosisamyotrophic lateral sclerosis (ALS)SummaryMuscle cramps may occur due to dehydration and imbalances in water and electrolyte levels. Muscle fatigue and damage may also contribute to muscle cramps.Rehydrating, replenishing electrolytes, and stretching may all help resolve dehydration cramps. If muscle cramps are severe or frequent, it is important to contact a doctor to determine the underlying cause.