It's basically an imbalance of the Thyroid gland, causing either slow or fast heart rate and palpatations, low or high metabolisms.All of which is easily treated but can very serious if neglected. Your doc would give you a blood test to determine if you've gone under active or over active, then prescribe medication to right the chemical imbalance. But some of the symptoms are reflected in the eyes, twitching, dry, sometimes sore eyes, dry mouth causing insatiable thirst.
What you have may very well be nothing more than a temporary facial tick, but i'd get it checked out to be on the safe side, now that i have my medication i no longer have the eye twitching or palpatations ( only when Everton play )