Ask HN: Why is social media so strict about medical advice

As the scope of what is considered part of “medicine” increases, it’s becoming increasingly hard to find or ask about very simple problems on forums like Reddit. For example you aren’t allowed to even mention pain in the context of a fitness question on Reddit, otherwise you get banned. This is honestly fucking stupid because every source of pain is not some serious medical issue that ONLY a doctor can solve. Sometimes you just need a few stretches or pointers to solve it yourself. This kind of thing is not allowed to happen anymore. Not to mention how access to medical care only gets harder and is frequently just bad.

Is there any actual legal reason why Reddit is so strict on this? Are there laws or other systemic factors causing more restrictive platforms or is it cultural?