Nervous system conditions such as multiple sclerosis (MS) and Parkinson’s disease may cause internal vibrations, which feel like tremors that happen within your body. Treatments like medication and physical therapy may help manage this symptom.

Internal vibrations are like tremors that happen inside your body. You can’t see internal vibrations, but you can feel them. They produce a quivering sensation inside your arms, legs, chest, or abdomen.

Internal vibrations aren’t as life-altering as external tremors. For example, you won’t physically shake while trying to pour a cup of tea or write a letter. Internal vibrations also aren’t the same as vertigo, which is another symptom of some neurological conditions. Vertigo feels like the world is spinning around you.

Still, internal tremors can feel unpleasant. And because they aren’t visible, these tremors can be hard to explain to your doctor. Keep reading to learn more about possible causes for your internal tremors and next steps.

Tremors are caused by damage in your brain affecting the nerves that control your muscles. Internal vibrations are thought to stem from the same causes as tremors. The shaking may simply be too subtle to see.

Nervous system conditions such as Parkinson’s disease, multiple sclerosis (MS), and essential tremor can all cause these tremors. One study reported that 33 percent of people with Parkinson’s disease had internal vibrations. Thirty-six percent of people with MS and 55 percent of people with essential tremor also reported feeling internal vibrations. Sometimes, anxiety can cause or worsen the tremors.

Most people with internal tremors also have other sensory symptoms, such as aching, tingling, and burning. The other symptoms you have with the vibrations can give clues to which condition you have.

Symptoms of Parkinson’s disease include:

  • tight muscles that are hard to move
  • slow, shuffling, stiff movements
  • small handwriting
  • quiet or hoarse voice
  • loss of your sense of smell
  • serious look on your face, called a mask
  • trouble sleeping
  • constipation
  • dizziness

Symptoms of essential tremor include:

  • small movements of the arms and legs, especially when you are active
  • head nodding
  • twitching in your eyelids and other parts of your face
  • quivering or shaky voice
  • trouble with balance
  • problems writing

Symptoms of MS include:

  • numbness in your arms, legs, face, and body
  • stiffness
  • weakness
  • fatigue
  • trouble walking
  • dizziness and vertigo
  • blurred vision or other sight problems
  • trouble controlling urination or bowel movements
  • depression

If you’re having internal vibrations, see your primary care doctor for an exam. Also make an appointment if you have symptoms such as:

  • numbness
  • weakness
  • trouble walking
  • dizziness

Your doctor will start by asking about your symptoms and medical history. You’ll have tests done to check for signs of neurologic conditions that can cause tremors. Your doctor will ask you to perform a series of tasks. These can test your:

  • reflexes
  • strength
  • muscle tone
  • feeling
  • movement and walking ability
  • balance and coordination

The doctor may also order one or more of these tests:

  • electromyogram, which measures how well your muscles respond to stimulation
  • evoked potential tests, which use electrodes to measure how well your nervous system responds to stimulation
  • lumbar puncture (spinal tap), which removes a sample of fluid from around your spinal cord to look for signs of MS
  • magnetic resonance imaging (MRI) scan, which shows lesions in your brain and spinal cord

Your doctor might refer you to a neurologist. A neurologist is a specialist who treats disorders of the nervous system.

Read more: Tests for multiple sclerosis »

To get the right treatment, first you need an accurate diagnosis. Sometimes internal vibrations will improve once you treat the condition that’s causing them. If your doctor can’t figure out the reason for your tremors, you might need to see a specialist for more tests.

Drugs for an underlying condition

Parkinson’s disease is treated with carbidopa-levodopa (Sinemet), pramipexole (Mirapex), and ropinirole (Requip). These drugs increase the amount of dopamine in your brain or they mimic the effects of dopamine. Dopamine is a chemical messenger that helps your body move smoothly.

Essential tremor is treated with a type of blood pressure drug called a beta-blocker. It can also be treated with antiseizure drugs.

MS treatment depends on the type of MS and its progression. It may include steroids to bring down inflammation in the brain and spinal cord. Other treatments include disease-modifying drugs like interferon and glatiramer acetate (Copaxone).

Drugs to control tremors

Certain medications can also specifically help control tremors. These drugs include:

  • anticholinergic drugs like trihexyphenidyl (Artane) and benztropine (Cogentin)
  • botulinum toxin A (Botox)
  • tranquilizers such as alprazolam (Xanax) or clonazepam (Klonopin), if anxiety causes your tremors

Other options

Working with a physical therapist can help you gain better muscle control, which may help with tremors.

If other treatments haven’t worked, your doctor might recommend surgery. In a technique called deep brain stimulation (DBS), the doctor implants electrodes in your brain and a battery-operated generator in your chest. The generator delivers electrical pulses to parts of your brain that control movement.

Internal tremors aren’t dangerous. They can be uncomfortable enough to interfere with your daily life, however. Whether this symptom improves depends on what’s causing the tremors and which treatment you get.

Finding the right treatment might involve some trial and error. If the first medication you take doesn’t work, go back to your doctor. See if you can try something else. The tremor might not go away entirely, but you may be able to control it enough that it no longer bothers you.

A tremor that no one can see can be hard to describe to your doctor. To help you explain this symptom, start keeping a diary of your tremors. Write down:

  • at what time of the day they happen
  • what you were doing when they started
  • what they feel like
  • how long they last
  • what other symptoms you have with them, such as dizziness or weakness

Bring this diary with you to your appointments. Use it as a guide during conversations with your doctor.