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Dr. David
Dr. David, Board Certified MD
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Experience:  Board Certified Physician
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What causes fasciculations in muscles when the muscle is slightly

Resolved Question:

What causes fasciculations in muscles when the muscle is slightly contracted but that stops when fully tensed?
Submitted: 3 years ago.
Category: Medical
Expert:  Shantal-Mod replied 3 years ago.

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Expert:  Dr. David replied 3 years ago.
This is Dr. David

there is not one condition which causes this.

fasciculations can happen in normal people normally

low potassium and low magnesium levels can cause fasciculations

fatigue and not enough sleep and dehydration can cause fasciculations as well.

do you have fasciculations at rest?
Customer: replied 3 years ago.

i get infrequent fascics at rest. It tends to happen when stressed / tired.


However these fascics when i lightly contract the muscle happen and have happened continuously for the last 14 months whenever I lightly contract the muscle. It happens between the thumb and index finger, the outside of the thigh and the inside of the foot.


I have read people with bfs complaining of the same thing. Its just it hasn't stopped in the 14 months. Its like a flickering but it stops when i rest the muscle.


I do occasionally get a twitch after i've contracted the muscle, a bit like it can't calm down.

Expert:  Dr. David replied 3 years ago.
it does sound like you have benign fasciculation syndrome

you should see your doctor and get a blood test to check your potassium and magnesium blood levels as these can affect your nerves and motor function and could cause fasciculation.

don't stress about these fasiculations. they are benign and not a sign of something more serious

let me know if you have other questions.

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Customer: replied 3 years ago.

thanks for getting back to me.


I have had these fasciculations, especially in the muscle between my thumb and forefinger for approximately 14 months now. I feel i've lost some subcutaneous fat on the hand in question.


In something like ALS, how soon would you notice real weakness if a muscle such as that was twitching?

Expert:  Dr. David replied 3 years ago.
you keep worrying about ALS

you haven't had weakness in a year

I would not be worried about ALS.
Dr. David, Board Certified MD
Category: Medical
Satisfied Customers: 45937
Experience: Board Certified Physician
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