Tremors are defined as involuntary shaking movements, and tremors commonly occur in a person's hand. Three types of hand tremors can happen: A resting or static tremor occurs when the hand is at rest, and will stop when the hand starts moving; kinetic or intention tremor occurs when the hand is moving, and will stop when the hand is still; postural or action tremor occurs when the hand stays in a position for some time, such as when holding an item.
Consuming certain substances can cause hand tremors. Too much caffeine can cause the jitters in the hand. According to the National Institutes of Health, alcohol has also been linked to hand tremors. Alcoholism, excessive drinking and withdrawal from alcohol can all lead to hand tremors. Some illicit drugs and prescription drugs can also result in hand tremors, which can happen when the drug is being used or during a withdrawal from the drug. Hand tremors are worse during withdrawal of some drugs, such as cocaine.
Specific diseases have hand tremors as symptoms. Parkinson's disease, a neurological condition, is identified by tremors and muscle rigidity. Hand tremors from Parkinson's disease are resting tremors. Multiple sclerosis is another neurological disease that has hand tremors as a symptom, though these hand tremors are intention tremors. An overactive thyroid can cause postural tremors unless treated.
According to the National Institutes of Health, normal aging and low blood sugar are two common causes for hand tremors. Stress, anxiety or fatigue can result in postural tremors, though these tremors will go away when the stressor or fatigue is alleviated. However, brain damage can also be the reason for a hand tremor. A stroke or brain tumor, which can disrupt normal brain function, are also possible causes.