Is it normal to have around 40 V in your body, when touching your plugged, ungrounded laptop?
The power supply has a certain amount of leakage current. The leakage is coupling through the isolation transformer.
That open-circuit floating voltage you’re seeing is typical and within safety limits for a consumer device. You probably also saw it drop to a low value (a couple of volts or so) when you touched the laptop. That should tell you how weak this current actually is.
The applicable safety standards limit this current to 3mA or so. In most cases this will be lower than that - 1 or 2 mA or so. You can measure that, too, using the mA AC scale on your meter.
That said, you could be sensitive to it. Try using your laptop only off battery and see if that makes a difference. If it doesn’t, it may very well be an ergonomic issue like your doc is probably thinking. If it is, you could try connecting your laptop to a ground.