Tremors are typically caused by neurological disorders or conditions, the use of certain drugs, alcoholism, mercury poisoning, liver failure or an overactive thyroid, according to the National Institute of Neurological Disorders and Stroke. Some forms of tremor are genetic, and others have no identifiable cause.
Tremors are an involuntary, rhythmic muscle movement that commonly impacts legs, hands, arms, face and voice, states the National Institute of Neurological Disorders and Stroke. It is common for an otherwise healthy person to develop a tremor. Although not life-threatening, it can be both embarrassing and make it difficult to perform routine tasks such as writing or holding a fork. In some cases, tremors are triggered by stress, strong emotion, physical exhaustion, or certain postures and movements.
Various categories of tremor conditions include essential, dystonic, cerebellar, orthostatic, and psychogenic or functional tremor, according to the National Institute of Neurological Disorders and Stroke. Tremor exhibits different characteristics within each category. Essential tremor is the most common form and may be mild for a long period of time or progressive over the course of a few years. Parkinsonian tremor, described as a resting tremor, is often the first symptom of Parkinson's disease. Tremor may also be the result of peripheral neuropathy, a condition wherein disease, injury, systemic illness or an abnormality in the central nervous system causes nerve damage.