Here is a link to photos of hands with focal dystonia. For me, my left hand cramps up (I am right handed) while I am cooking. I put an oven glove over it to hide it. It's ugly and hurts.
https://www.researchgate.net/figure/Focal-hand-dystonias-upper-panel-with-task-specificity-Writers-cramp-and-Barbers_fig1_221928595
Focal is one example of dystonia that impacts the hands, but there are many other types. This is from the Dystonia Foundation on the other types of dystonia:

Segmental: Dystonia that affects two or more connected body parts, for example the face, neck, and arm.

Generalized: Dystonia that affects the torso and at least two other body areas, frequently the limbs.

Isolated or Primary: Dystonia is the only neurological symptom a person appears to have.

Acquired or Secondary: Dystonia that appears to have a specific cause such as drug reaction, brain injury, or as a symptom of another neurological or metabolic disorder.

Paroxysmal Dyskinesias: Dystonia may occur in episodes, often with additional movement symptoms.

Functional: Dystonia may occur as part of a functional neurological disorder.
https://dystonia-foundation.org/what-is-dystonia/