QUICK ANSWER
"El" is a form of "el", a definite article which is often translated as "the". "La paciente" is a form of "paciente", an adjective which is often translated as "patient". Learn more about the difference between "el" and "la paciente" below.
el(
ehl
)A definite article is a word that identifies a noun as specific or known to the speaker (e.g., the girl).
paciente(
pah
-
syehn
-
teh
)An adjective is a word that describes a noun (e.g., the big dog).
1. (tolerant)
This means that the noun can be masculine or feminine, depending on the gender of the noun it refers to (e.g., el doctor, la doctora).
a. patient
En este momento, el hospital está tratando a doscientos pacientes.Right now, the hospital is treating two hundred patients.