It may appear when performing movements such as drinking from a glass, tying a button or eating soup. In these cases it is called action tremor. It can also appear when that part of the body is not being used, such as when the hand trembles while walking. In these cases it is called rest tremor.

The causes of tremor are multiple and its diagnosis is based on clinical and family history, as well as general and neurological examination data. In many cases, analytical tests are essential to rule out metabolic problems that may cause tremor. In others, anatomical (Cranial Magnetic Resonance Imaging) or functional (SPECT or PET) neuroimaging testsmay be needed to demonstrate or exclude some tremor-causing diseases. Tremor analysis may also be performed using surface electrodes that record the frequency and pattern of contraction of the muscles producing the tremor to help determine its cause.

Treatment of tremor depends on its severity and cause. In general, there are pharmacological treatments that can improve it and some people may benefit from botulinum toxin injections.

In people with tremors that interfere with motor activities of daily living and do not respond satisfactorily to other treatments, functional stereotactic surgery can be performed. The most common procedure involves implantation of a deep stimulation electrode in the thalamic nucleus.