Involuntary shaking is usually caused by some form of nerve damage that corrupts the communication between the brain and muscle cells in the body, explains MedicineNet. Associated health conditions include multiple sclerosis, amphetamine use, mercury poisoning, stroke, psychiatric prescription medications, alcoholism, brain injury, corticosteroid use, drug withdrawals and liver failure.
Shaking is also commonly associated with generalized anxiety disorders, Parkinson's disease, diabetes, exposure to cold temperatures and dehydration, according to Calm Clinic. People who suffer from chronic anxiety experience a prolonged fight or flight mode that contributes to the presence of adrenaline in their bloodstream. An overabundance of this hormone can cause a person to shake uncontrollably due to the increased shot of energy that is coursing through the body.
Occasional anxiety is usually not a medical concern and is designed to help a person think and react quickly in emergency situations. For people with serious anxiety disorders, this function glitches and becomes frequent and uncontrollable. Once adrenaline enters the bloodstream, a person can do nothing to control the body's response to the hormone except to wait it out or try to expend the energy as quickly as possible. This can be achieved by engaging in physical activity, finding a private place to yell loudly or taking several deep, controlled breaths until the sensation of shaking passes, explains Calm Clinic.