Regarding your thread title
So for me, type 2 when the bloods were out of control had a few issues: blurred vision, fatigue and a very (very) bad temper
drugs brought the levels down and the temper went with it luckily. The other issues crop up, but blurred vision when I have to much sugar so that’s something I stop
the fatigue took me years to work out, I thought choccy or bad stuff did it, it does but so do carbs, have potatoes at lunch and I’m nearly asleep mid afternoon so lower carb has helped with that.
my hba1c is now nearly at normal level due to weight loss, lower carb and exercise (all three linked in may ways). Aim is to drop drugs and be in remission
so... your friend can aim to near or actually normal levels of blood sugars that will stop the potential complications and live a pretty normal life except potentially need a permanent change to their diet (depending what it is now)
now... honestly speaking, it can be a very dangerous condition, but it is generally in our control to stop that happening but the worst thing I did was allow drugs to control it and not change my ways. That’s the best advice I can find, look on the forums, be very wary of the nhs diet advice, and take control, don’t let it control you