A sudden growth of a mole on the left thumb may be due to hereditary factors or external stimuli such as friction.
Moles can grow on any part of the body at any time. The majority of moles are hereditary and most of them are benign, so there is no need to worry about them or treat them.
Individual moles may develop pigmentation due to long-term exposure to external stimuli, such as chemical stimuli, sunlight stimuli, or long-term friction with foreign objects. This kind of hyperpigmentation will not become malignant and does not require special treatment. However, moles that grow on the palms of the hands, the abdomen of the fingers, and other parts of the body that are susceptible to friction and extrusion, in order to prevent malignant changes, it is best to go to the hospital in a timely manner to remove the mole by surgery.
If it affects the beauty, you can go to the dermatology department of the nearest hospital or beauty salon for laser treatment. Commonly used treatments can be carbon dioxide laser or fractional laser, both of which have better results.