Breakdown of Я пью лекарство, чтобы лечить свои суставы.
я
I
пить
to drink
лекарство
medicine
свой
one's own
Questions & Answers about Я пью лекарство, чтобы лечить свои суставы.
Why is it пью (drink) instead of 'take'?
In English, we 'take' medicine, but in Russian, you use пить (to drink) for taking most medications, even pills! You will often hear пить лекарство or принимать лекарство (to accept/receive medicine), but never брать (to physically grab).
Why use чтобы here?
Чтобы means 'in order to'. When the subject of both actions is the same (you are taking the medicine and you are treating the joints), you use чтобы followed directly by an infinitive verb, like лечить here.
Could I say мои суставы instead of свои суставы?
You could, and people would understand you, but свои is much more natural here. Свой is a reflexive pronoun that means 'one's own'. Because the joints belong to the subject of the sentence (Я), Russian strongly prefers свои over мои.
If I wanted to say 'my joints hurt' instead of treating them, how would I use the lesson's grammar?
You would use the structure from this lesson. Since joints (суставы) are plural, you use the plural verb болят. The sentence becomes У меня болят суставы (literally: 'By me ache the joints').