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"Las medicinas" is a form of "medicina", a noun which is often translated as "medicine". "Los síntomas" is a form of "síntoma", a noun which is often translated as "symptom". Learn more about the difference between "las medicinas" and "los síntomas" below.
la medicina(
meh
-
dee
-
see
-
nah
)A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
1. (science)
a. medicine 
Mi novio estudia medicina en Yale porque quiere ser cirujano.My boyfriend is studying medicine at Yale because he wants to become a surgeon.
2. (medication)
a. medicine 
Mary dejó de tomar su medicina debido a los efectos secundarios.Mary stopped taking her medicine because of the side effects.
el síntoma(
seen
-
toh
-
mah
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
1. (medicine)
a. symptom 
La fiebre puede ser un síntoma de muchas enfermedades.Fever is a symptom of many different illnesses.
2. (signal)
a. symptom 
El alto desempleo es un síntoma de una crisis económica.High unemployment is a symptom of an economic crisis.
b. sign 
La falta de comunicación es un síntoma de que las cosas no están bien entre ustedes.Lack of communication is a sign that things are not going well between you.
c. indication 
Su comportamiento es síntoma de descontento.Their behavior is an indication of dissatisfaction.