The Gemara says, “Chash bi’chol gufo ya’asok ba’torah” (Eiruvin 54a). If you are sick, then you should learn Torah in order to heal. Would the Rav say that one can overlook this chazal and instead go to sleep in order to get better?
When a person is not feeling well, let him look in the Torah. Of course! And what will he see in the Torah? In the Torah he’ll see that it says, “Rapo yi’rapeh.” It says in the Torah that you have to go to the doctor if you are sick. And included in that is that you have to take care of your body so that it can heal. Someone who damages his fellow must pay, among other things, for refuah. He has to pay for that person’s healing. And besides that, the Gemara is full of discussions about healing and health. Everywhere you look, it’s full of healing. And therefore there’s no question that learning Gemara will teach you that you have to make sure that you heal.
However, suppose that you’re not able to diagnose your illness. Or even if it was diagnosed and you’re taking medications. Still, the segulah of learning Torah is also a way to heal. And that’s because Hashem says, “If you’re able to utilize your life for learning Torah, then you deserve to get well and live longer.” If you are not feeling well and you make an effort to be oisek ba’torah anyhow, then you are showing that you know why you’re in this world – you know how to utilize your time in this world – and just because of that, Hakodosh Boruch Hu will give you more time in this world to accomplish.
And therefore learning is a segulah for getting well. However, does that mean that you’ll stop eating?! No, you have to eat anyhow, even if you’re learning Torah. So even if you’re learning you’ll have to make sure to take your medicines and sleep as much as your body requires to heal.