What are Muscle Cramps?
Muscle cramps are a spontaneous contraction of one or more muscles. It can be quite painful, but in many cases they’re not a cause for concern.
The cramp will typically only last a few seconds and can be triggered by various factors including: holding the same position for too long, lack of fluids, physical activity or other illnesses.
The leg muscles are the most common place to experience a cramp. One in three adults experience the symptom in their calf muscle during night-time. (1)
Causes
When a muscle cramp occurs the muscle is unable to relax. It can sometimes be seen from outside as it becomes hard and tense.
The cramp can also keep returning until it has fully resolved. It can occur in any muscle and can involve one or several at the same time.
A muscle cramp is believed to be caused by a malfunction in the nerves. This biological glitch can be caused by an illness, medication or something less serious such as dehydration. (2)
Typical causes of muscle cramps can include:
Physical Activity
If excessive pressure is put on a muscle during exercise it can cause minor damage to tissues which will increase the chances of cramps, especially while dehydrated.
It’s a common occurrence in athletes or sportsmen and is not considered a serious issue. (3)
Pregnancy
Muscle cramps can also happen for women who are pregnant. It could be due to the extra weight putting more strain on the leg muscles, as well as the baby compressing the nerves to the legs. (4)
Dehydration
Our bodies need water to function properly, dehydration can be described as when the body lacks sufficient fluid.
There are several links between dehydration and poor physical performance. This is especially commonly seen in children and people who exercise. (5)
When the body doesn’t get the right amount of fluids the muscles aren’t getting the salt and nutrients they need therefore are more likely to cramp up.
It’s important to drink lots of fluids especially when active or in warm temperatures.
Dystonia
Dystonia can best be described as a movement disorder of the muscles. This condition causes the muscles to contract involuntary and cramp up. (6)
When a contraction occurs, it will cause either twisting, repetitive movements or an abnormal posture. It can be quite painful for some and can affect one muscle or several muscles at the same time.
Symptoms include foot spasms and a dragging foot after exercise. It can also cause the person to find handwriting difficult. (7)
Motor Neuron Diseases (MNDs)
MNDs are a group of different neurological diseases which destroy cells controlling muscle activities for speaking, swallowing, breathing and walking. (8)
As these conditions progress, they weaken and also cause wasting or muscle loss. As a result the person will not be able to control voluntary movements. (9)
As the muscles weaken, they become prone to experiencing spasms and muscle cramps.
Peripheral Artery Disease (PAD)
PAD is when fat, cholesterol and other substances found in blood build up in the arteries. (10)
The accumulation can harden over time and restrict the organs or limbs from receiving the oxygen enriched blood they need. This lack of oxygen can cause muscle cramps, particularly in the legs and buttocks. (11)
Medication
It’s not unusual for some types of medications to cause muscle cramps. It’s mostly from diuretics pills otherwise known as water tablets.
This type of medicine is generally taken to treat high blood pressure or in some cases to prevent kidney stones. It can sometimes interfere with the body’s level of salts and minerals thereby cause a cramp. (12,13)
Acute Kidney Failure
This is when the kidneys stop working typically in less than two days. The kidneys suddenly can’t rinse waste from the body and balance the electrolytes. This means the muscles aren’t receiving the nutrients they require which can lead to cramps. (14)
Menstruation
It is common for girls and women to feel discomfort and slight pain in the lower abdomen due to their period.
It’s normal to feel abdominal cramps during a cycle. However, some females can experience severe pain, where it may even be carried into the legs. (15)
Symptoms
Muscle cramps are generally a symptom of another condition. But there are a few ways to characterize them.
Sudden Sharp Pain
It’s not always the case muscle cramps come with a warning sign. This means the affected muscle will be hit by a sudden sharp pain at onset. (16)
The muscle will feel tense, maybe it can even make the area affected look abnormal.
Location
Usually muscle cramp will affect one muscle, but it can also appear in groups and spread to different areas.
The most common place for a muscle cramp is in the calf. But if it occurs in another location, it could be a sign of something else. (17)
Duration
As a general rule a muscle cramp will only last seconds or at worst few minutes. However, if the cramp is prolonged or recurrent, it could be a clue of another condition. (18)
Trigger
Some people develop cramps during or after exercise at a certain level of exertion, though some can experience them at rest. (19)
Recent Onset
If muscle cramps have started to materialize more often, it could be a sign of an intercurrent illness. This is when a new disease meddles with a current one.
However, if muscle cramps have been an issue since youth, it could be an inherited condition. (20)
Diagnosis
Muscle cramps are usually symptoms of other events going on in the body. As previously mentioned it can be serious, yet mostly they’re easy to treat.
Doctors will try and diagnose the cause of the muscle cramp by asking questions about the symptoms you are experiencing.
If your doctor feel there’s a need for further diagnosis, a blood sample might be drawn for examination. (21)
Questions
In order to get to the right diagnosis of what caused the muscle cramp your doctor will most likely ask you a few questions.
They will want to you to describe the type of symptoms encountered and also what events have taken place prior to the cramp. For example, whether you were performing any type of physical exercise or even question your fluid intake.
Other questions could include: medical history, any recent medical treatments, possible alcohol abuse.
If a diagnosis still remains uncertain, your doctor will request further tests to pinpoint the problem.
Physical Examination
If your doctor suspects an underlying cause he/she may perform a physical examination by checking your reflexes, muscle strength and even your sense of balance.
Further Tests
To check for disorders in the muscles your doctor might do a electromyography (EMG) This test works to diagnose any problems in the lower motor neurons. It will be inserted into a muscle using a thin needle where it will measure the activity. (22)
An ankle-brachial index (ABI) test may be used if your doctor suspects a condition like PAD. This test works to compare the blood pressure in your arms and legs,
it will reveal how fluent your body’s blood flow is. (23)
Blood Test
Your doctor may request a blood test to check the levels of calcium, potassium or magnesium in the blood. Low levels can trigger muscle cramps and should be treated.
Other blood tests can be examined for kidney and thyroid functions. (24)
FAQ
What are muscle cramps? Muscle cramps are involuntary spontaneous contractions of a muscle which can be quite painful.
What causes muscle cramps? Muscle cramps can have a range of possible causes. It’s usually due to overexertion or dehydration. But some illnesses and disorders such as dystonia or kidney problems can also trigger muscle cramps.
How do doctors test for the cause of muscle cramps? Typically a doctor will ask questions about the muscle cramp, location and duration. To check for underlying issues doctors request a blood test.
When should you see a doctor for muscle cramps? When the pain is overbearing and does not improve with simple stretching. Additionally, if the cramps keep returning and last for longer periods.
Can muscle cramps be prevented? Muscle cramps can be prevented by exercising within your limits and gradually increasing intensity. By stretching before and after exercise and drinking plenty of fluids.
What can relieve muscle cramps? Stretching and massaging the muscle will usually help. Hot applications during the cramp and cold application after will help relieve the pain. Nonsteroidal anti-inflammatory medicines can also help keep the pain at bay. (25)
Can a muscle cramp affect the muscle structure? No, generally muscle cramps are a dysfunction which causes pain and it doesn’t affect the muscle structure. (26)
Why are muscle cramps common during sleep? The exact cause is not known, but it is believed to be caused by an abnormal processing of the essential elements your muscle needs for basic function. (27)
Summary
Muscle cramps can be a painful inconvenience of an involuntary muscle contraction which almost everyone will experience at some point in their lives. However it is commonly seen in older people and athletes.
In most cases it’s brought on by something like dehydration or overused muscles. Yet it can sometimes be a symptom of a serious underlying issue which may need further treatment.