Why do your legs twitch when you fall asleep?

In the evening after work we rush home. The day, as usual, was difficult: meetings and communication with many people who are not always pleasant for us, running around accompanied by hassle, rush jobs, conflicts with management, etc. Home is our quiet haven where you can relax, unwind, relieve yourself of the burden of fatigue and daytime negativity. And so, after a delicious dinner, we are sitting in our favorite cozy armchair or lying on a comfortable sofa. The TV usually flickers, on the screen of which the heroes of the next series save the world, we plunge into a doze … And suddenly a sharp jolt, from which the legs tremble, makes us wake up. Similar sensations come from electric shocks. A familiar picture, isn’t it? Where does this push come from, and why do the legs twitch when falling asleep?

Myoclonus: signs and characteristics of the syndrome

In medicine, the phenomenon of flinching during sleep, in which involuntary sharp muscle twitching occurs, is called nocturnal myoclonus. When the body reaches the maximum level of relaxation, active muscle contractions can occur, which are called positive myoclonus.

The appearance of a similar syndrome is also possible when muscle tone decreases. In this case, the myoclonus is called negative. The described syndrome also has an alternative name – hypnagogic flinching.

Local parts of the body can be affected by myoclonus, for example: only the right leg or even one of the muscles of the leg. In more complex cases, all limbs can twitch, sometimes also the facial muscles responsible for facial expressions. By the nature of the course of myoclonic seizures, they are classified into rhythmic, arrhythmic, reflex, spontaneous, asynchronous, synchronous.

What is the essence of myoclonus? The brain is the control panel of the body. The movements of each part of the body are provided by certain muscle groups. To start moving, muscle tissue must receive a corresponding signal from the brain, which enters the channels of the nervous system. The result of such signals is the excitation of muscle fibers, followed by muscle tissue contraction. If for some reason there is a one-time excitation of a whole group of channels of the nervous system, then the start of the body or its individual parts begins. This phenomenon is called myoclonic seizures.

The hypothalamus is to blame for everything.

In the intermediate part of the brain, there is a section called the hypothalamus. This area is formed by a large number of cell blocks and is responsible for the normal functioning of many body systems. For example: it regulates metabolic processes, controls the endocrine, cardiovascular, and also controls the autonomic and many other systems. When a person falls asleep, the first phase of sleep begins, a decrease in body temperature occurs, a drop in blood pressure. The breathing pattern changes: a much smaller volume of air is inhaled into the lungs and exhaled. This whole complex of changes in the indicators of the body’s work is similar to the processes characteristic of death.     

The hypothalamus regards such a situation as dangerous, and in order to “resurrect” the body, to return all its systems to an active state, it sends a discharge, arranges a shake-up. Result: a sharp increase in muscle tone, expressed in a shudder of the body.

Hypnagogic startle has no age, social or gender restrictions. This syndrome can manifest itself in one form or another in each of us. How to determine: is it worth worrying and make an appointment with a neurologist if you find myoclonic seizures or not? The defining moment is the duration of the startle during sleep. If this phenomenon is short-lived, sometimes present in the initial phase of sleep, then you should not worry. This level of myoclonus is within the normal range, does not threaten health and good sleep.

Things are much more serious if myoclonic convulsions accompany sleep throughout the night. This pathology does not allow you to sleep, the body does not recover. Pathological myoclonus indicates significant health disorders and can provoke the appearance of new diseases. In such circumstances, of course, you cannot do without qualified medical care. The earlier the treatment begins, the more effective the results will be.

Physiological myoclonus

The vast majority of people experience hypnagogic flinch. If the manifestations of myoclonus do not last long at the beginning of falling asleep, then they do not pay attention to this. In the morning, there are no memories of short-term convulsions. Only relatives can see this and tell.

Among neurologists, the most common theory of the occurrence of nocturnal myoclonus. It lies in the fact that the brain perceives as a danger a slowdown in the course of the body’s vital processes during the transition to sleep. However, this is not the only opinion; there are several more versions that deserve attention:

  • Perhaps myoclonic seizures occur when sleep phases alternate. The sleep process is complex and consists of several phases: slow, fast, shallow and deep sleep. During the transition from one phase to another, there is a sharp change in the indicators of brain activity, which provokes the emergence of impulses in many channels of the nervous system at the same time. The result of this is the appearance of nocturnal myoclonus.  
  • Some experts in psychology and neurology are of the opinion that startle on falling asleep occurs due to excessive stress on the nervous system. During the day, a person experiences many events, while experiencing a lot of different feelings. Negative emotions cause stress. And its accumulation leads to an overload of the nervous system, which during sleep, as it were, “rewinds” unpleasant situations.  
  • Another theory of the occurrence of hypnagogic flinching is an insufficient amount of such a trace element as potassium in the body. It is a part of all soft tissues, bones, blood, and its deficiency adversely affects the functioning of the liver, brain, nervous and cardiovascular systems. If the tests show that there is not enough of it in the body, the doctor will prescribe the appropriate drugs.
  • A nervous tic, which is a monotonous, involuntary, rapid contraction of muscle tissue, can cause body tremors when drowning. In children, it usually goes away with age. Adults should receive treatment that will reduce severe symptoms.
  • Myoclonic seizures can be triggered by excessive physical exertion. This is especially true for elderly people, as well as those who do not have the appropriate physical training.

Whatever the cause of the short-term nocturnal myoclonus, this symptomatology is not a pathology. If there are signs of physiological myoclonus, then don’t panic – they are considered a natural component of healthy sleep.

Pathological myoclonus

If a short tremor of the legs during the transition to sleep should not cause fear and anxiety, then myoclonic convulsions during the day during the waking period are a reason to attend to. Sometimes, after experiencing serious stress, which is necessarily expressed in overloads of the nervous system, some manifestations of daytime myoclonus are permissible. If this does not occur chronically and there are no relapses, then there is no cause for alarm yet. However, when the syndrome manifests itself repeatedly throughout the day, and then it repeats on subsequent days, then, most likely, pathology can be assumed.  

The causes of pathological myoclonus can be different. Frequently recurring progressive day and night hypnagogic seizures are one of the hallmarks of epilepsy. Moreover, they can affect both local areas and the whole body. Various manifestations can provoke an attack, for example: a strong thunderstorm, lightning strikes, loud music with a flashing light. Doctors explain the causes of epileptic seizures by an insufficient amount of oxygen entering the brain, as well as by degeneration of brain cells.

There is also an essential variant of myoclonus, which in patients begins in childhood, being a hereditary disease.

In addition to these, there are a number of conditions against which the symptoms of pathological myoclonus may appear:

  • Viral encephalitis. When the virus enters the brain substance, inflammation begins. The carriers are already sick people or infected insects, sometimes the disease is caused by the herpes simplex virus.
  • Diseases affecting the spinal cord, cerebellum, brain stem, which are hereditary.
  • Cumulative reticulosis (accumulation diseases). A complex of hereditary or acquired (acquired) conditions of pathologies that cause metabolic problems, damage to the cardiovascular or central nervous system. 
  • Degenerative processes in the basal nuclei, which are located in the white matter of the brain.
  • A sharp violation of the blood circulation in the brain (stroke). Sudden fainting or paralysis may be a sign of illness.
  • An inflammatory process in the nerve endings that affects the fibers. It occurs due to diseases of various internal organs. Damage to nerve fibers can also be the result of poisoning with a toxic substance or an overdose of a medical drug.

Only specialized doctors can determine the cause of pathological myoclonus. As a rule, if a disease is suspected, an electroencephalogram is prescribed, blood is donated for tests. If signs of pathological myoclonus are found, you should not postpone the trip to the medical center, neglected diseases are treated more difficult and longer.

Restless legs syndrome

Restless legs syndrome (RLS) can be one of the manifestations of pathological myoclonus. It has alternative names – Ecombe’s disease or Willis disease, after the names of the researchers. Its symptoms are the trembling of the legs during the period of falling asleep, further continuing throughout the sleep. Convulsions, as a rule, affect the feet and legs, sometimes only one leg twitches. Unpleasant sensations are not limited to shaking. They are accompanied by itching and a constant need to move the legs. The disease can appear not only in the elderly, but also in young people, even children. Most of the patients are women. According to statistics, about ten percent of people on the planet suffer from restless legs syndrome. When a neurological examination is carried out, it is impossible to identify RLS, only the clinical manifestations of this disease help determine the correct diagnosis. 

Restless legs syndrome occurs in two varieties: symptomatic and idiopathic, they are treated with different methods:

  • Symptomatic RLS appears in a patient due to various diseases of the nervous or somatic system. If the diagnosis is correct, therapy is carried out, then the symptoms of the syndrome disappear. Possible diseases: rheumatoid arthritis, thyroid disorders, diabetes mellitus, anemia, renal failure. The onset of RLS symptoms can also be caused by taking certain medications (antihistamines, anticonvulsants, antidepressants, etc.).
  • The idiopathic variant of restless legs syndrome appears, one might say, “from scratch”, that is, the disease begins suddenly. Such RLS is inherited, although some overlap of other factors is required for vivid manifestations of its symptoms. The disease usually occurs in a patient before the age of thirty, it does not respond to treatment, it is only possible to smooth out the symptoms with medications.

A characteristic feature of the treatment of RLS with drugs is its duration, the therapy takes many years. This requires the need to achieve the greatest effect by taking the smallest doses of drugs. Over time, addiction to drugs occurs, which means that you have to increase the dosage. The combination of drugs should be avoided and limited to monotherapy.

Sleep paralysis

Myoclonus can also manifest as sleep paralysis. Its symptomatology has been familiar to people since antiquity, and it is covered with various mystical stories. The patient suffering from this disorder is conscious, but cannot even move. This state is accompanied by growing panic, fear, visions. It was the visions that created the mystical infernal flair for this disease. A patient in a state of sleep paralysis sees monsters, aliens, otherworldly voices, chilling sounds, etc. The condition is aggravated by a feeling of suffocation, heaviness in the chest area. At the same time, the patient trembles, his pulse quickens, breathing becomes difficult. Fortunately, all these conditions accompanying sleep paralysis do not threaten health, but they make you go through a few very unpleasant minutes.

The cause of the manifestations of the syndrome can be various kinds of diseases of the nervous system. Their range is wide: from manic-depressive psychosis to somnambulism and narcolepsy. Although most often sleep paralysis appears due to an imbalance in the nervous system.

Possible reasons:

  • frequent severe stress;
  • drug addiction or alcoholism;
  • chronic lack of sleep;
  • overdose or many months of taking certain medications (tranquilizers, antidepressants).

In addition to the listed factors of the appearance of the syndrome, sleep paralysis can be inherited. In most cases, drug treatment is not required. After confirming the diagnosis, doctors recommend changing the daily routine, sleeping at least eight hours a day, leading an active lifestyle, avoiding stress, giving yourself a massage, etc.


Often, myoclonus can manifest itself as a syndrome of periodic limb movements (SPDK). A patient suffering from such a disease rhythmically flexes and unbends the big toes and joints of the ankle during sleep. The events take place in cycles of twenty to forty seconds. In most cases, such a deviation makes you wake up, while the patient does not remember the episode. Periodic limb movement syndrome is almost always accompanied by restless legs syndrome, the causes of SPDK and RLS are similar.

Manifestations of myoclonus in pregnant women

According to research results, about a quarter of women experience myoclonic seizures during pregnancy. The reasons for this lie in the peculiarities of the physiological state during such a period, first of all, we are talking about toxicosis. Most often, manifestations of nocturnal myoclonus appear in women during the second and third trimester of pregnancy. Typically, this is restless legs syndrome. In rare cases, myoclonus may occur immediately after childbirth. 

Symptoms in children

Parents can pay attention to how the baby jerks its legs during the transition to sleep. Don’t panic. It should be remembered that the structure of a baby’s sleep is different from ours. This is due to age and different stages of development of the body – the older the person, the more complex all the processes. The duration of the deep sleep period for an adult is two to three hours, while in infants it lasts approximately one 50-60 minutes. Deep sleep gives way to superficial sleep, and during this transition, the baby may shudder. That is, twitching during the surface phase indicates that the child is simply dreaming. Myoclonus can also occur in adolescent children. This period of life is characterized by an active reorganization of the body, therefore, sometimes malfunctions of the nervous system may occur.     

Prevention and treatment methods

If you find symptoms of hypnagogic flinching in yourself or in your loved ones, there is no need to panic. Medicine has sufficiently studied this disease, so there are a number of effective methods of getting rid of it.

If the myoclonus is pathological, then you will have to undergo a course of drug therapy, which will help eliminate the disease that causes convulsions.

If it turns out that myoclonus is of a physiological type, then a set of the following measures will help get rid of it:

  • First of all, you need to develop a daily routine and try to adhere to it. You need to accustom yourself to go to bed early, and wake up earlier in the morning, and it is better to have an alarm clock. The duration of sleep should be at least eight hours, if this is not enough – nine or ten hours. 
  • Complete rejection of bad habits. Alcoholism, drug addiction, tobacco smoking are some of the main causes of myoclonus.
  • Active lifestyle, sports activities. A light warm-up in the morning and a jog in the fresh air will bring results quickly. If you can’t run, you should try to walk more.
  • Avoiding large doses of caffeine. If you are a fan of strong tonic drinks (coffee, tea), you should significantly reduce their consumption due to the stimulating effect of caffeine. Replace your usual drink with fruit compote or chamomile tea.
  • Inclusion in the diet of foods containing magnesium, calcium, potassium (kefir, vegetables, herbs).
  • In the autumn-winter time, hypothermia should be avoided, especially you should try to keep your hands and feet warm.
  • Avoid activity on the eve of sleep. You can take a warm bath, light scented candles, turn on calm music.
  • Creation of comfortable conditions for sleeping. It is unacceptable to use old bedding, especially pillows with a feather of a bird. An orthopedic mattress and pillow should be purchased. Loud sounds, bright light should not interfere with falling asleep.
  • Control the microclimate in the bedroom. The room must be ventilated, monitor the normal level of humidity. If the air is dry, especially during the heating season, then it is advisable to buy a humidifier.

The listed measures will help you regain restful sleep. All these actions are recommended for those who do not face the manifestations of myoclonus – this will become an effective prevention of the disease. A restful sleep will allow you to recover after a hard day, give new strength to achieve your goals.

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