My mother has them. She though was never diagnosed with them by her neurologist, at least that's what she told me whenever I asked about it. I asked if he had mentioned 'functional tremors' to her but she doesn't remember. I was always interested because I am afraid to get them as well.
With her it started slowly, she noticed it in her wrists.
It developed until she could no longer lift a cup without spilling, and the neurologist told her there was medication for it when she finally saw him. She asked if there were side effects and he explained them. She is quite proud of what she said next: "I said, 'Doctor, would you take them?' and he said 'Erm, no', so I said I would not take them either."
She has very, very strong tremors that slow her down. She has eye drops that she needs twice a day and she carefully prepares since it takes her time to get them in, but she manages. She still is living independently after my father died, and does not want medication against the tremors. I discussed multiple options including Botox, knowing she would absolutely not want those 😊 It can be helpful but she doesn't want them fixed, and feels it's too late now that she's getting on in life. She got used to living with these tremors, she can't use a smart phone for instance, or a bigger tablet, because her fingers mistype and mistouch or already touch while she says "No no I didn't touch anything." She sometimes presses a button without realising it (but I heard it), so yes, they can be difficult to manage but you can live with them if you're careful. But my heart breaks every time I see her trembling hands, I feel very sad now I think about them, but also glad that she is such a trooper.