A tremor is an involuntary shaking motion that can occur anywhere in the body, but most commonly affects the hands and arms, according to MedlinePlus, a service of the National Institutes of Health. Everyone experiences a slight tremor during hand movement and this is not a reason for concern. When hand and arm tremors are persistent or severe, they can indicate an underlying medical condition.
Caffeine Sensitivity
Caffeine is a drug that is produced naturally in the leaves and seeds of certain plants. Caffeine is defined as a drug because it stimulates the central nervous system. Caffeine is commonly found in coffee, tea, soft drinks, energy drinks and chocolate. In people with normal tolerance to caffeine, moderate amounts, which are defined as 200 to 300 mg, cause alertness, an energy boost and elevated mood. Those with caffeine sensitivity experience adverse responses to caffeine. These responses include anxiety, dizziness, headaches and tremors, especially in the arms and hands, according to KidsHealth, an information website sponsored by the Nemours Foundation. The amount of caffeine needed to produce these effects varies between individuals based on body size and weight and normal amount of caffeine intake.
Hypoglycemia
Hypoglycemia is characterized as low levels of the sugar glucose in the blood. Glucose is the body's main source of energy. Inadequate amounts in the blood can affect the brain as well as other areas of the body. Symptoms of hypoglycemia include confusion, blurred or double vision, heart palpitations, anxiety, sweating, increased hunger and tremors, often seen in the hands and arms. Hypoglycemia is most often associated with diabetes, but can also occur as a result of alcohol abuse, certain medications, liver diseases, tumors and endocrine disorders, according to MayoClinic.com. Hypoglycemia can also occur as a normal response to extended periods of fasting.
Parkinson's Disease
Dopamine is a chemical neurotransmitter in the brain that plays an important role in several body functions including thinking, voluntary movement, behavior and memory. Parkinson's disease is a type of motor system disorder that is characterized by the gradual loss of the brain cells that produce dopamine. According to the National Institute of Neurological Disorders and Stroke, there are four characteristic symptoms of Parkinson's disease--tremors in the hands, arms, legs and face; stiffness of the limbs; slow movement; and instability. Other possible symptoms include emotional changes, difficulty chewing and speaking, urinary and bowel problems and problems with the skin. As the disease progresses, symptoms worsen and tremors and instability can significantly interfere with daily life. The National Institute of Neurological Disorders and Stroke notes that some of those with Parkinson's disease become completely disabled, whereas others are able to function fairly well on their own.
