Medical Terminology for Shakes
The medical term for "shakes" is tremor, defined as an involuntary rhythmic oscillation of a body part produced by reciprocally innervated antagonist muscles. 1
Core Definition and Classification
Tremor is the most common movement disorder encountered in clinical practice and represents rhythmic oscillatory movements of body parts. 1, 2 The term encompasses various subtypes based on when the shaking occurs:
- Resting tremor: Occurs when the body part is in repose, classically seen in Parkinson's disease 1
- Postural tremor: Occurs with maintained posture 1
- Kinetic/Action tremor: Occurs with movement 1
Context-Specific Terminology
In Neonates and Infants
Jitteriness is the preferred term for tremor-like movements in newborns, which differs from seizures by being stimulus-sensitive, ceasing with passive flexion of the affected limb, and predominantly affecting limbs rather than face. 3 This can result from:
- Maternal substance exposure (SSRIs, opioids, benzodiazepines, caffeine) causing withdrawal symptoms in 55-94% of opioid-exposed neonates 3
- Metabolic derangements including hypoglycemia, hypocalcemia, and hypomagnesemia 3
In Pregnancy
Hunger-related tremors in pregnant women are typically manifestations of hypoglycemia and should be managed with 20 grams of rapidly absorbed carbohydrate (4 glucose tablets, 4 ounces of juice, or 1 tablespoon of honey). 4
Common Pitfalls in Terminology
Avoid using "shakes" in medical documentation—this colloquial term lacks diagnostic precision. 5 Similarly, the European Society of Cardiology guidelines note that terms like "faint" are too imprecise for scientific contexts, though useful for patient communication. 5
Important Distinction from Syncope
Myoclonus (brief involuntary muscle jerks) can occur during syncope but does not constitute tremor, as these movements are not rhythmic oscillations. 5 The presence of myoclonus in syncope does not imply epileptic seizures. 5
Clinical Classification Framework
Tremors are categorized by:
- Frequency: Measured in Hz (e.g., essential tremor 4-8 Hz, parkinsonian tremor 4-6 Hz) 1
- Amplitude: Degree of oscillation 1
- Anatomical distribution: Upper extremities, head, legs 1
- Associated conditions: Parkinson's disease, essential tremor, cerebellar disease, peripheral neuropathy, alcohol withdrawal, medication effects 1, 6
The key to accurate diagnosis and treatment is precise classification of the tremor type based on observable clinical characteristics rather than using non-specific terms like "shakes." 7