I am not sure what is going on here without some additional information, but I will give some basic ideas.
If you notice any redness or inflammation around the finger nails, one possibility would be an infection of the nail fold, which is called a paronychia. This is more common if you have frequent manicures or if you bite your fingernails.
Another possibility would be arthritis
of the finger joints. This is a common problem in older and middle aged adults. Osteoarthritis, which is the 'wear and tear' type of arthritis, often affects the last knuckle on the fingers, which could be interpreted as pain under the finger nails.
Finally, Raynaud's phenomenon, which is a condition in which the blood vessels in the fingers clamp down, especially under the influence of exposure to cold temperatures, is a possibility. With Raynaud's phenomenon, the tips of the fingers often turn white or blue when the blood flow slows down, and this can cause pain.
As you can see, these ideas are all over the place! This just emphasizes how hard it can be to give accurate information over the internet, and why you should go see your primary care doctor
to help sort this out a little better.