Swellling is edema. When a body part is swollen it's described as edematous. Dactylitis is a more specific term meaning sausage-like swelling of a finger (or toe).
Paronychia is the term for an infected nail on a finger.
oedema
Indurated
Varicose veins, swollen tortuous veins, are called varices in medical terms.
Edematous
brachydactyly
Finger abduction is the medical term meaning spreading the fingers apart.
Digital necrosis
Swelling or edema of the arm is an indication of inflammation or disturbances of blood or lymph flow causing a swollen appearance of the hand, forearm or fingers.
Digit- or Dactyl- is the medical terminology combining form meaning fingers and toes.dactyl/o
You could call it the fifth finger, fifth digit, or digiti minimi.
abnormally swollen veins
nail