A tremor is an unintentional and uncontrollable rhythmic movement of one part or one limb of your body. A tremor can occur in any part of the body and at any time. It’s usually the result of a problem in the part of your brain that controls muscular movement. Tremors are not always serious, but in some cases they may indicate a serious disorder. Most tremors can’t be treated easily, but they will often go away on their own.
It’s important to note that muscle spasms, muscle twitches, and tremors are not the same thing. A muscle spasm is the involuntary contraction of a muscle. A muscle twitch is an uncontrolled fine movement of a small portion of a larger muscle. This twitch may be visible under the skin.