Why do i keep having twitches in my thumb. probably 10-20 times a day?

Muscle spasm?: Is it like an eyelid twitch? It suddenly starts , out of nowhere, and goes on and off for a few seconds to minutes.Non-painful? If so, it is likely an innocent little muscle spasm.

It is hard to say : Without seeing what you mean by twitches but a common phenomena is fasciculation where the muscle seemingly twitches rapidly, this can be form pain or orrotation locally but can also be due to endocrine or mineral balance or due to a muscle or neurological problem, or just from overactivity and fatigue. If it continiues speak to your primary care.