What Is Hand-Arm Vibration Syndrome (HAVS)?

Hand-Arm Vibration Syndrome (HAVS) is a group of vascular, neurological, and musculoskeletal conditions that impact hand functioning and are associated with long term use of vibrating tools. HAVS can lead to painful and disabling disorders of the nerves, blood vessels, and joints in the hands and arms.

HAVS causes changes in sensations of the fingers. Often, people with the condition experience numbness or tingling in the fingers, muscle weakness, and sometimes episodes of white fingers. Usually, people only develop these symptoms if they have been working consistently with vibrating tools for at least 10 years. The best treatment and prevention of HAVS is to stop working with vibrating tools.

There are 3 types of HAVS injuries. These types include:

• Neurological injuries. This type of injury occurs when there has been damage to nerve cells in the fingers, hands, or arms. Early warning signs are tingling and numbing. This may eventually lead to reduced hand functionality. A common type of this injury is carpal-tunnel syndrome. Raynaud’s phenomena is another type of neurological injury, in which a person experiences episodes of white fingers (fingers turn white, then blue, then red) when exposed to something cold or damp.
• Muscular injuries. This occurs when there has been damage to the muscle structure. This could reduce grip strength.
• Vascular injuries. This occurs when the vibration injures the capillaries in the hands and fingers causing vasospasm. This condition reduces the blood flow to the hand and causes numbness and blanching (whiteness of the hands or fingers).

The overall number of people affected by HAVS has significantly decreased in recent years due to workplaces becoming more aware of how to reduce the risk of developing HAVS.

Signs and Symptoms

Once HAVS has fully developed, the damage is irreversible. It is important to seek treatment before it has a chance to lead to permanent damage. Some people develop symptoms in months, while others take years to develop symptoms or may never develop symptoms. Symptoms of HAVS vary between individuals.

Common symptoms include:

• Numbness
• Tingling
• Loss of sensitivity in the affected area
• Finger whiteness (comes and goes)
• Muscle weakness or loss of muscle strength
• Diminishing grip strength
• Aches and pain in the hands and arm

Causes

HAVS is typically caused by long term use of vibrating tools. Examples of tools include:

• Jackhammers
• Drills
• Gas powered chainsaws
• Electric grinders and other electrical tools 

Risk Factors

Risk factors include working in environments that cause you to be working with vibrating tools for a sustained amount of time. Workplaces that do not keep their equipment up to date or in good working condition pose a greater risk for developing HAVS. Additionally, you are at a much greater risk of developing HAVS if you have been working consistently with vibrating tools for at least 10 years.

Diagnosis

Diagnosing HAVS includes your doctor evaluating your symptoms, taking a thorough medical history, and performing a physical examination. Your doctor may also ask questions about your work or living environment. In some cases, your doctor may also test your grip strength and fine motor movement ability. Additionally, your doctor may recommend tests to rule out other conditions.

Treatment

The primary treatment for HAVS is to stop using vibrating tools. This will stop symptoms from getting worse, but it may not reverse the damage that has already been done. Your doctor may also recommend that you avoid taking certain medications that contribute to circulation issues in the fingers. These medications include:

• Beta-blockers
• Decongestants (that contain adrenaline)
• Certain migraine medications (propranolol; medications that contain ergot-derivatives)
• Certain oral-contraceptive medications 

Additionally, doctors recommend that you stop smoking because smoking narrows the arteries that pump blood to the fingers. There are also medications that can help to relax the blood vessels, which may help to reduce symptoms of HAVS. In some instances, people have benefited from physical therapy in the reduction of symptoms.

Prevention

There are several ways to prevent HAVS from developing. Prevention measures include:

• Do not use vibrating tools for sustained amounts of time over the course of several years
• Hold the vibrating tools loosely in varying positions
• Keep vibrating tools well-maintained
• Use tools that have features that reduce vibration impact
• Be sure to use the tools appropriately and not grip too tightly for too long
• Work for short bursts (10 minutes or less), taking frequent breaks, rather than working for longer durations of time without a break
• Use a job sharing or job rotation approach
• Keep yourself warm (specifically your hands) while working with the tool
• Wear appropriate work gloves
• Stop smoking 

Complications

Complications of HAVS occur when you experience permanent or irreversible neurological, vascular, or muscular damage. People with permanent damage may experience constant hand numbing or tingling, reduced grip strength, difficulty with fine motor skills, aches and pains, and episodes of white fingers.