If you trained more than a decade or two ago, there's a good chance you were taught that pain works like a fire alarm: damage a tissue, a signal travels up to the brain, and the brain reads out a pain level roughly proportional to the harm done. It's a tidy model. It's also, we now know, badly incomplete, and understanding why matters for how you explain pain to clients, how you set expectations, and how you talk about what your hands are actually doing.

Most of what walks through your treatment room door is exactly what it looks like: tension headaches, sports injuries, digestive complaints, stress, and poor sleep. Complementary therapy is very good at helping with all of these. But every so often, a symptom presents that isn't what it seems, and the safest, most professional thing you can do is recognise it and refer the patient on to a medical practitioner.

This is what "red flags" means in clinical practice. It isn't about being alarmist or diagnosing disease yourself. It's about knowing which symptoms and combinations of symptoms carry a higher likelihood of an underlying condition that needs medical input, so you can make an informed decision about referral rather than an anxious guess.