Most of the time, a child who shakes, trembles, or twitches is experiencing something completely harmless. Newborns jerk in their sleep, toddlers shudder briefly for no clear reason, and feverish kids shiver as their bodies try to raise their temperature. That said, shaking can occasionally point to something that needs prompt medical attention, from a febrile seizure to an electrolyte imbalance. The key for parents is knowing how to tell the difference, and the details of what was happening right before and during the episode matter far more than the shaking itself.
Sleep Twitches in Newborns
If your baby jerks, twitches, or makes rhythmic limb movements while sleeping, there is a good chance you are seeing benign neonatal sleep myoclonus. It looks alarming: a sleeping newborn’s arms or legs suddenly start jerking in clusters, sometimes for several minutes. Parents often worry it could be a seizure. The critical distinction is that these movements stop the moment the baby wakes up. Seizures, by contrast, do not obey the sleep-wake boundary in the same tidy way.
A review of the medical literature covering 164 infants found that this type of myoclonus occurred across all sleep stages, vanished after arousal, and could actually be triggered by rocking or repetitive sounds. Interestingly, the jerks sometimes worsened when someone held the limb still or when anti-seizure medication was given, which is the opposite of what you would expect with epilepsy. About a third of affected infants still had the movements at three months, but the condition resolves on its own and does not lead to developmental problems.1Pediatrics. Benign Neonatal Sleep Myoclonus: A Review of the Literature
The practical takeaway: if your baby only twitches while asleep and stops completely when you wake them, mention it to your pediatrician at the next visit rather than rushing to the emergency room. Getting a short video of the episode on your phone is one of the most useful things you can do, a point that matters for many types of childhood shaking and that we will return to later.
Shuddering Attacks in Infants and Toddlers
Shuddering attacks are brief, involuntary trembling episodes involving the head and upper body that happen during normal waking activities. They look like a rapid whole-body shiver, the kind you might see when someone tastes something sour. The child stays fully conscious throughout and goes right back to whatever they were doing once it passes. These episodes are not seizures, and they do not impair awareness or development.2PubMed Central. Shuddering attacks: A benign phenomenon in children
What makes shuddering attacks tricky for parents is that they can look remarkably similar to infantile spasms or myoclonic jerks, which are genuine seizure types that do require treatment. The resemblance sometimes leads to unnecessary workups and even inappropriate anti-seizure medication. In most children, shuddering attacks disappear by about age two without any intervention.3Journal of Pediatric Epilepsy. Shuddering Attacks in an Infant
If you think your child is having shuddering attacks, note a few things: Does the child stay aware and responsive? Does the episode last just a few seconds? Is there any pattern to when they happen, such as during feeding or excitement? That information helps a pediatrician distinguish a benign shudder from something that needs further investigation.
Fever, Chills, and Febrile Seizures
Fever itself can make a child shake in two very different ways, and confusing one for the other is common. The first is rigors, which are essentially intense shivering. When an infection triggers fever, the brain’s thermostat resets to a higher target temperature. Chemicals released during infection alter the activity of temperature-sensing neurons in the hypothalamus, causing the body to generate heat through shivering in order to reach that new, higher set point.4PubMed. Role of the preoptic-anterior hypothalamus in thermoregulation and fever During a rigor, the child is awake, responsive, and simply cold. The shaking stops once their temperature stabilizes at its new level.
Febrile seizures are an entirely different event. These happen in roughly 2 to 5 percent of children between the ages of six months and five years, typically when a fever spikes rapidly. During a febrile seizure, the child loses consciousness, their body may stiffen and then jerk rhythmically, and they are unresponsive to their surroundings. Doctors divide febrile seizures into “simple” and “complex” categories. Simple febrile seizures last under 15 minutes, are generalized rather than focused on one side of the body, and do not recur within a 24-hour period. Complex febrile seizures are longer, focal, or recurrent, and they receive more medical attention because they carry a slightly higher risk of future epilepsy.
Research comparing children who had complex versus simple febrile seizures has found structural differences in certain brain regions, with children who experienced complex febrile seizures showing lower volume in parts of the basal ganglia.5PubMed. Volumetric magnetic resonance imaging differences between complex febrile seizure and recurrent simple febrile seizure Separately, iron deficiency anemia appears to be more common in children with complex febrile seizures, and some researchers have suggested an inflammatory component to the condition.6PubMed. Differences in iron deficiency anemia and mean platelet volume between children with simple and complex febrile seizures None of this means parents caused the seizure or could have prevented it. Most children who have a febrile seizure never develop epilepsy, and simple febrile seizures do not cause brain damage.
How to tell the difference in the moment: if your child is shivering with a fever but responds when you talk to them, looks at you, and can hold a cup of water, that is almost certainly a rigor. If their eyes roll back, they go stiff, and they do not respond to your voice, that is a seizure and warrants a call to emergency services, especially if it is their first one or lasts longer than five minutes.
Low Blood Sugar and Electrolyte Problems
Children’s bodies are less forgiving of missed meals, dehydration, and stomach bugs than adults’ bodies are. When blood sugar drops too low, the nervous system loses its primary fuel source, and the body responds with trembling, sweating, irritability, and sometimes confusion. Toddlers who have been vomiting, refused to eat for a stretch, or just ran around all morning without a snack are the classic candidates. The shaking tends to be a fine, fast tremor of the hands and legs rather than the rhythmic jerking of a seizure, and it resolves quickly with food or a sugary drink.
Electrolyte imbalances are a less common but more urgent cause. When calcium, magnesium, or potassium levels fall too low, or when the blood becomes overly alkaline, muscles can go into sustained involuntary contraction, a state called tetany. This can look like stiffening, twitching, or cramping rather than classic shaking.7PubMed Central. Don’t Take It ‘Lytely’: A Case of Acute Tetany In children, the usual culprit is prolonged vomiting or diarrhea that depletes minerals faster than the body can replace them. Infants who are fed improperly diluted formula or excessive water are also at risk. If your child’s shaking is accompanied by muscle stiffness, spasms in the hands or feet, or a recent bout of illness with significant fluid loss, an emergency evaluation is warranted because correcting the imbalance usually stops the symptoms quickly.
Vitamin B12 and Other Nutritional Gaps
In parts of the world where maternal diets are low in animal products, vitamin B12 deficiency is a recognized cause of tremor and developmental regression in infants. B12 is critical for the nervous system’s myelin sheath, the insulation that lets nerve signals travel efficiently. When an exclusively breastfed infant’s mother is severely B12-deficient, the baby can develop involuntary movements, developmental regression, and a clinical picture that resembles a neurological disease.8PubMed Central. Infantile tremor syndrome: Role of Vitamin B12 revisited
This is uncommon in populations with varied diets, but it is worth knowing about if you follow a strict vegan or vegetarian diet and are breastfeeding. The fix is straightforward: maternal supplementation during pregnancy and lactation, or direct supplementation of the infant, typically reverses the neurological symptoms if caught early. Pediatricians who suspect the issue can check a simple blood test.
Thyroid-Related Tremor
An overactive thyroid gland speeds up nearly everything in the body, and one of its visible effects is a fine, fast tremor, usually most noticeable when the child holds their hands out flat. The tremor is thought to result from the thyroid hormones ramping up certain receptors in the nervous system that make muscles more excitable.9PubMed Central. Thyroid Disorders and Movement Disorders—A Systematic Review – Section: Hyperthyroidism and Hyperkinetic Movement Disorders Along with the tremor, you would typically see other signs: weight loss despite a good appetite, a fast resting heart rate, difficulty sleeping, irritability, or sweating more than usual.
Hyperthyroidism is not common in children, but when it occurs, the tremor is one of the easier symptoms for a parent to spot. Graves’ disease is the most frequent cause in the pediatric age group. If your child has a persistent fine tremor and seems wired or anxious without an obvious reason, a thyroid function blood test can rule this in or out quickly.
When Shaking Looks More Like Wobbling
Not all abnormal movement in children is tremor. Ataxia, which looks like sudden clumsiness, unsteady walking, or a loss of coordination, sometimes gets described by parents as “shaking” because the child’s movements are jerky and uncontrolled. The most common causes of sudden-onset ataxia in children are accidental ingestion of medications or toxins, and post-infectious inflammation of the cerebellum, the brain region that coordinates movement.10PubMed Central. Ataxia in children: early recognition and clinical evaluation
Chickenpox is one of the classic infections linked to cerebellar inflammation in children. The ataxia typically appears a few days to a week after the rash starts, though it can sometimes show up before the rash or after it has cleared. Children between two and eight years old are most commonly affected. The good news is that post-infectious cerebellar ataxia usually resolves on its own over weeks, though it still warrants a medical evaluation to rule out other causes.10PubMed Central. Ataxia in children: early recognition and clinical evaluation
The red flag to watch for with ataxia is timing. If your child was perfectly coordinated yesterday and today cannot walk straight or keeps falling over, that warrants same-day medical attention regardless of whether a fever or rash is present. Accidental medication ingestion is always a possibility in toddlers, and confirming or ruling it out early changes the treatment plan.
Functional Tremor in Older Children
In school-age children and adolescents, a tremor can occasionally arise without any structural problem in the brain. Functional tremor, the most common type of functional movement disorder, produces real, visible shaking that is not faked or imagined, but it originates from how the nervous system processes signals rather than from damage to brain tissue. What sets it apart diagnostically is that the tremor changes with distraction. If you ask the child to tap a rhythm with the opposite hand, for example, the tremor may shift frequency to match the tapping or briefly disappear.11PubMed. Functional tremor
Functional tremor is not the same as “making it up.” It is a recognized neurological condition, and it can be just as distressing and disabling as tremor from other causes. Stress, anxiety, and major life changes are often present in the background, but pointing that out to a child or teenager in a dismissive way tends to make things worse. Treatment usually involves physical therapy, sometimes cognitive behavioral therapy, and an explicit explanation to the child that their brain is sending the wrong signals rather than that something is broken. Recovery rates are generally good when the diagnosis is made early and the child feels believed.
Medications That Can Cause Shaking
A number of common pediatric medications list tremor or shakiness as a side effect. Albuterol, the bronchodilator used in asthma inhalers and nebulizers, is one of the most frequent offenders. If your child just had a breathing treatment and their hands are shaking, the medication is the likely explanation. The tremor typically fades within an hour or two as the drug is cleared. Stimulant medications used for ADHD can produce similar fine tremor in some children, as can certain anti-nausea drugs and even some antibiotics at higher doses.
In most cases, medication-related tremor is a nuisance rather than a danger. But if the shaking is severe, persistent, or accompanied by a racing heart, vomiting, or confusion, contact your child’s prescriber. Dose adjustments or switching to a different medication usually solves the problem.
The Power of a Phone Video
Perhaps the single most useful thing you can do when your child has an episode of shaking is capture it on video. Childhood movement episodes are often brief and unpredictable, and they rarely perform on cue in a doctor’s office. A short recording gives a clinician information that no verbal description can match: the speed and rhythm of the movement, whether the eyes are open or deviated, whether the child responds to their name, and how the episode ends.
Research has confirmed that home video recordings meaningfully improve diagnostic accuracy. In one study examining how well clinicians identified epileptic versus non-epileptic events in children, videos increased the rate of correct diagnosis for non-epileptic events by about 12 percentage points compared to questionnaires alone.12PubMed Central. Clinical utility of home videos for diagnosing epileptic seizures: a systematic review and practical recommendations for optimal and safe recording That is a meaningful improvement when the alternative is a potentially unnecessary EEG, MRI, or trial of anti-seizure medication.
A few tips for recording: try to keep the child’s whole body in frame, including the face. Avoid zooming in on just the shaking limb. If possible, say the child’s name during the episode so the doctor can see whether the child responds. Note the time of day, what the child was doing beforehand, and how long the episode lasts. Even a shaky, poorly lit phone video is more diagnostically valuable than a careful written description after the fact.
Red Flags That Call for Immediate Attention
Most childhood shaking does not require an ambulance. But certain features should prompt you to seek emergency care rather than waiting for a scheduled appointment:
- Loss of consciousness: the child’s eyes are rolled back, they do not respond to their name, and the episode lasts more than a few seconds.
- Duration beyond five minutes: any seizure-like episode that does not stop on its own within five minutes needs emergency intervention, because prolonged seizures can become harder to stop the longer they continue.
- Blue lips or face: color change around the mouth during an episode suggests the child is not breathing adequately.
- First seizure ever: even if it stops quickly, a first seizure in a child warrants same-day evaluation to rule out infections, metabolic problems, or structural issues.
- Shaking after a head injury: tremor or seizure following a fall or blow to the head needs imaging to check for bleeding.
- Possible ingestion: if there is any chance the child got into medications, cleaning products, or other substances, treat the shaking as a poisoning until proven otherwise.
- High fever with a stiff neck: this combination raises the concern for meningitis and requires emergency evaluation.
If you are unsure whether what you saw qualifies as an emergency, calling your pediatrician’s after-hours line or a nurse hotline is a reasonable middle step. Describe what happened, mention how long it lasted, and note whether the child returned to normal afterward. If the child bounced right back to playing within a minute and seems completely themselves, it is usually safe to schedule a regular appointment, especially if you captured video.
What the Doctor’s Evaluation Typically Involves
When a child presents with unexplained shaking, the evaluation usually starts with a careful history rather than a battery of tests. Clinicians want to know the child’s age, the timing of episodes, what the child was doing before and after, whether consciousness was preserved, and whether there were any associated symptoms like fever, vomiting, or a recent illness. Family history of seizures or movement disorders is relevant too. In many cases, the history alone, especially when paired with a video, narrows the diagnosis enough that no further testing is needed.13PubMed Central. Two children with tremor
When tests are ordered, they are typically targeted. A complete blood count and metabolic panel can catch anemia, low calcium, and blood sugar issues. Thyroid function tests screen for hyperthyroidism. An EEG, which records brain electrical activity, is ordered when seizures are suspected but is not needed for every child who trembles. An MRI of the brain is reserved for cases where a structural problem is plausible, such as new-onset ataxia, a tremor that is worsening over time, or focal neurological findings on exam.
Parents sometimes feel frustrated when a doctor examines their child, hears the story, and says it sounds benign without ordering scans. In pediatric neurology, that kind of confident clinical diagnosis based on history is often the gold standard. A normal exam and a characteristic story for benign sleep myoclonus or shuddering attacks is more reassuring than an MRI, because the scan would be normal anyway and does not add diagnostic value. Trust the process, bring your video, and ask questions if the plan is not clear.