Likutei Moharan 267:1/ליקוטי מוהר"ן רס״ז:א׳

1Shavuot is a cure for the lungs. This is because the five lobes of the lungs parallel the Five Books of the Torah (Tikkuney Zohar #25, p.70a). On Shavuot, when we receive the Torah, we are capable of receiving new vitality.