For the nail discoloration, since it has been persistent and has turned brownish-black in one finger, it’s important to get it examined by a dermatologist to rule out fungal infection or, rarely, other causes.
Regarding the shoulder and arm pain, since it is persisting despite medications, worsening at night, and now affecting both arms, it may need further evaluation with imaging like X-ray/MRI or a neurologist or orthopedic review to check for nerve compression or cervical spine issues. Meanwhile, avoid overuse, apply warm compresses, and continue gentle stretching as advised by your doctor.
Health Tips
Please don’t self-medicate further without review.