Have you ever felt the sudden twitch in your body while you were trying to fall asleep? You woke up, and it seemed like you were dreaming about missing a step, slipping, or falling. These events are called sleep starts, or hypnic or hypnagogic jerks, and they are quite common.
Have you ever felt the sudden twitch in your body while you were trying to fall asleep? You woke up, and it seemed like you were dreaming about missing a step, slipping, or falling. Your heart rate was increased, and it took you a few minutes to go back to sleep, and sometimes you might even had a hard time meeting the Sandman again. If you have ever experienced this, don’t worry, you are not alone, and it is completely normal.
These events are called sleep starts, or hypnic or hypnagogic jerks, and they are quite common. Almost everybody experiences it at some point in their lives, and they can also affect anybody, no matter your sex, racial background, or age.
Sleep starts are usually harmless, and they don’t require any medical assistance. However, there are some reported cases of hypnic jerk anxiety, where person’s events were so frequent and unpleasant, that they developed a negative attitude towards going to sleep. Sometimes, sleep starts can be a sign of some underlying sleep or a mental disorder.
Hypnic jerks are a part of a wider variety of involuntary movements called myoclonus. Sleep starts are not considered a sleep disorder, and they usually don’t require any treatment. There are some things you can try to lower the chances of these events if you experience them frequently or they feel startled by them.
Myoclonus refers to a sudden twitching of muscles. If sudden muscle contractions cause it, it is called positive myoclonus, and in case of muscle relaxation it is negative myoclonus. They can be single events, or they could happen in a sentence or a specific pattern.
Besides sleep starts, hiccups are another excellent example of myoclonus. While these are entirely harmless, severe cases of myoclonus affect a person’s ability to move, eat, or talk. Those are often a sign of some underlying condition, or brain and nerve damage, and need to be treated.
Myoclonus can develop as a result of head or spine injury, infections, liver or kidney failure, brain tumors, drug poisoning. Myoclonic jerks can also occur in patients who have multiple sclerosis, Alzheimer’s disease, Parkinson’s disease. They are frequent in people with epilepsy because the brain’s electrical signals are distorted.
There are some forms of myoclonus; here we listed the ones described by the National Institute of Neurological Disorders and Stroke (NINDS):
It is still unclear why do sleep starts happen, and researchers are trying to figure that out. It is most likely due to misfiring of neurons when some parts of the brain fall asleep faster than the others. Another interesting hypothesis says that hypnic jerks are an ancient primate reflex. They supposedly happen because of the relaxation that is sometimes misinterpreted as a falling out of the nest in the trees, so twitching happens to wake us up.
Whatever the cause, they are thought to affect most of the population, and they are more frequent in young children. Some risk factors are shown to increase the chances of sleep starts occurring. High intake of the caffeine and other stimulants, especially too close to bedtime may set it off. Emotional trauma, stress, poor sleeping habits, and high-intensity exercise before sleep are common triggers as well. Medication abuse, iron deficiency, and urea build up are also suspects for potential causes. Certain sleep disorders like obstructive sleep apnea can play a role too. Frequent unpleasant episodes of sleep starts need a medical examination, as they can lead to anxiety and sleep onset insomnia, or they can be a sign of a more complex underlying problem.
Other causes of sleep movements include:
In most cases, hypnic jerks can be improved through changing lifestyle habits like:
If your symptoms are persistent, and these sleeping tips don’t help you, you should consult a medical professional. They may need to do an overnight sleep study called a polysomnogram, where they will observe your brain waves, respiration and heart rate, and many other things. That way they can determine what is causing your sleep problems and prescribe the right treatment. Sleep starts can be treated with leg exercise, iron supplements, dopamine agonists in really bad cases, as well as other medical supplements.
Dusan is a biologist, a science enthusiast and a huge nature lover. He loves to keep up to date with all the new research and write accurate science-based articles. When he’s not writing or reading, you can find him in the kitchen, trying out new delicious recipes; out in the wild, enjoying the nature or sleeping in his bed.