Hi for over a week now my finger next to my thumb on my right hand keeps on twitching like a jerking movement like it tightens and spasms . age 35?

Spasm : Many possible causes. If it's just that one finger, you may be developing a trigger finger which may be able to be cured or significantly helped by a properly placed steroid injection. If you are having spasms in other muscles in your body, other potential causes may be an electrolyte imbalance (potassium, calcium) or the onset of a neurological disorder, so see a doctor.