Essential tremor - Causes of essential tremor

Research suggests that essential tremor may be caused by a change (mutation) in one of your genes. Genes are inherited units of information (DNA) that determine how your body grows and functions.

It is thought that the gene mutation affects the areas of the brain known as the cerebellum and the inferior olive, altering the signals sent along the nerves to the muscles.

Inherited and non-inherited essential tremor

At least half of essential tremor cases are inherited. This means that a faulty gene is responsible for the condition and is passed on to you from your parents. Conditions that are passed on in this way are known as autosomal dominant disorders.

If one of your parents has a faulty gene for essential tremor, you have up to a 50% chance of developing the disorder yourself. However, how old a person is when they first develop the condition and its severity can vary greatly between different family members.

Unfortunately, there is no simple test to determine whether your essential tremor is caused by one particular faulty gene.

There may not always be a family history of essential tremor as not everyone with the mutated gene will develop symptoms. Similarly, some people may develop the mutation without inheriting it from either parent.

Tremor triggers

Your tremor may be triggered or made worse by one or more of the following actions:

• making controlled or small, detailed movements, such as drinking a glass of water or writing
• eating
• putting on make-up
• shaving

Being tired, anxious, hot or cold is also likely to make your symptoms worse.

Other causes tremor

There are a number of other conditions or factors that can cause a tremor. These include:

• overactive thyroid (hyperthyroidism)
• Parkinson's disease, a long-term condition that affects the way the brain co-ordinates body movements
• multiple sclerosis, a condition of the central nervous system (brain and spinal cord) that affects the senses and the body's actions
• dystonia, a range of movement disorders that cause involuntary muscle spasms
• stroke, which very rarely may result in tremor with few other symptoms
• peripheral neuropathy, where the peripheral nervous system is damaged
• withdrawal symptoms when you stop drinking alcohol, which may affect people who were dependant on alcohol and have stopped or reduced their alcohol intake
• amphetamines and other stimulants
• medications, such as some antidepressants and some medicines that are taken for asthma
• caffeine, in tea, coffee and some fizzy drinks