When someone has trembling hands or involuntary movements in their arms, legs or head, people tend to conclude the shaking is a sign of Parkinson's disease.

However, the symptoms may be the result of a more common, less severe condition called essential tremor. Essential tremor can be confused with typical Parkinson's disease symptoms, but the two movement disorders are separate conditions.

Because these diagnoses can get tangled up, it's helpful to understand their differences.

First, let's explore the basics of each condition.

Essential Tremor

Essential tremor is the most common type of tremor. It's a neurological disorder that causes involuntary shaking, most often of the hands and arms. The condition is not life-threatening, though in severe cases it can cause disability.

Tremors start in the hands and arms and can affect the head and voice as well. Usually, it starts as a low-amplitude tremor, meaning the shaking is mild. The low-amplitude tremors may have a higher frequency, meaning there are many repetitions per second. As the condition progresses, which it may do with age, the tremors themselves may become more severe but with lowered frequency.

Doctors and researchers aren't sure what causes essential tremor, but it may be inherited. This thought rises from findings that people with a parent who has a genetic mutation for essential tremor are 50 percent more likely to have it as well, according to Mayo Clinic.

Even though essential tremor can happen at any age, it's most common in people older than 40 years and affects men and women equally.

Parkinson's Disease

Parkinson's disease is a neurological disorder that happens when nerve cells in the brain don't produce enough dopamine. The disease progresses over time, leading to more and more disability. The disease occurs more often in men than women and usually develops in people over 60.

Tremors are one of the most well-known Parkinson's disease symptoms and one that sends many people to their doctor for evaluation.

Parkinson's tremors usually start on one side of the body, commonly in the hands, and progress to the other side. The movements tend to be more forceful (high amplitude) with lower frequency.

The disease carries many other symptoms that help distinguish it from essential tremor, as well. Tremors may not always be the most prominent symptom, with other symptoms including stiffness in the body, slow movements and trouble with balance.

Recognizing the Difference

Parkinson's disease is much less common than essential tremor, and it presents itself in markedly different ways. While treatments overlap in some areas, getting the best care requires the right diagnosis. The two conditions have key differences to look for:

• Essential tremor doesn't cause associated health problems, while Parkinson's carries other symptoms, such as stooped posture and balance problems.
• Essential tremor may affect the voice box, but Parkinson's does not.
• Essential tremors are usually felt more when in motion, but Parkinson's tremors are felt more when at rest.
• Essential tremor symptoms can progressively get worse, but won't necessarily shorten the patient's life span. Parkinson's tends to progress over time and may shorten the patient's life span as the brain produces less and less levodopa over time.

For many people, essential tremor may be mild and may not interfere with daily life. However, any tremor that worsens should be evaluated by a doctor.

Medications, physical therapy, deep brain stimulation and other techniques may be used to manage tremors, depending on how severe they are. Your doctor can also offer tips to cope and ways to avoid triggers like caffeine and stress, so don't hesitate to seek professional advice if tremors are a part of your life.