Just had a couple of recent experiences.
I don't declare having sharp objects as it'd probably mean some form needs to be filled in, and given that perhaps 1 in 100 people will be carrying needles and tens of thousands of people pass through security each day, it won't be uncommon for them to see them on x-rays and be relaxed. And with tiny modern needles unless you were going to stab someone 4,000 times with them they would not make much of a weapon!
But on the way out of London, my hand luggage got stopped. The guy asked me if I had anything sharp inside and I said yes and explained, and he said he could also see the number of pens I had. He said reason bag was stopped was actually that while I had taken iPad out of bag, i'd then put it under bag so it had to be x-rayed again. But all fine.
Coming back through Geneva, I pinged the body metal detector, when the guy did the body touch search he felt my Dexcom sensor on my arm, so I then had to wait for a couple of minutes in full view before going behind closed curtain area where i rolled up my sleeve and showed him. His English not great, but he understood after a minute or so.
A further small annoyance that we encounter as T1s, but not end of the world.