Blood pressure check? No mystery there. Same for the trip to the scale–which is way off, of course. But what’s with the penlight and little rubber mallet? Here’s what your doctor’s looking for when he…

…asks you to say “ahh”
He’s looking for swelling or discolouration in your mouth and throat, which may indicate oral cancer. This test also checks if your palate and uvula – the punch bag at the back of your throat–contract at the same time. If they don’t, your gloss pharyngeal and vagus nerves may not be working properly. “This can signal problems such as a stroke, brain tumour or multiple sclerosis,” says Dr David Deci, a professor of family medicine at the University of Wisconsin.

…shines a penlight in your eyes
Your doc is testing your optic nerves, which transmit visual information to your brain, as well as the oculomotor nerves that control your eye muscles. “If your pupils don’t dilate or dilate too much, that could indicate nerve damage, “says Deci. That damage could involve the specific nerves or be centred in your brain, possibly as a result of a stroke or reduced blood flow.

…taps and presses on your abdomen
This helps detect an enlarged–and potentially infected–organ. “When I tap over your liver or spleen, the sound is dull. It becomes more resonant as I move off the organ, helping me gauge its size,” says Dr David Simel. Your doc may also press in as you take a deep breath. This pushes your diaphragm down, shifting your liver and spleen so they’re easier to feel.

…hits your knee with a small mallet
This classic reflex test exposes nerve or metabolism problems. If you have lower back pain, for example, and your leg barely budges when your doctor taps your knee, then some of your spinal nerves may be damaged, says Simel. An X-ray maybe the next step. A karate kick could indicate an overactive thyroid. In that case, flooding hormones can make your reflexes more forceful.