If you have pains already you should really take action. This is something that if not prevented and treated can lead to an operation and can even be permanent. Olafmeister have experienced this problem previously.
There is also toys that are suppose to help. Like a Powerball This will span at high a high RPM while you just hold it still.
If you feel general irritation and/or pain in your wrist (especially while gaming) You should get a Wrist Protector I recommend one with a metal metal rail. Just wear it when you are not playing or using your hands. Like when sleeping or while watching TV. Do not use it excessively tho. This will make your muscles weaker.
Take a break
You guys might also have heard about streamers and gamers dying after marathon gaming. This is usually due to blood clots forming in their legs, due to poor blood circulation. This can happen over longer periods of time if you are sitting down
for long periods of time.
It is important to stand up in a while. When working it is recommended that you stand for at least 30 minutes for every sitting 1 hour. But like that is going to happen. I recommend standing up for 2-3 minutes every 20 minutes. Which properly
is hard as well if you are playing competitive. But between matches or in the halftime, just stand for as much as you can. even if it is 15 seconds. Jump a few times, get that blood flowing.
I usually go pee, refill my water bottle, open a window or just go outside for a few minutes to catch some fresh air between games.
TL;DR : Stand up as often and as much as you can. Unless you wanna die from blood clots in your legs.
I cannot stress this enough. Water is what helps your bodys blood circulation, metabolism, regulation of body temperature, waste removal and detoxification.
If you game for a long time just drinking energy drink or sodas, this can be bad for your whole body (obviously) But lack of water can cause damage to your liver in the long run. Some studies even suggest that dehydration is a hazard in traffic.
This is because it will slow down your brain activity. You will react slower. Drink water, get better reactions, get global.
If you have a hard time tracking and/or remembering to drink water. Then there is various apps like This one that will lend you a hand.
Do not take your body for granted. You only have one. You might be fine now, but we are pretty much the first people to grow up with mouse and keyboards and this amount of PC usage everywhere. That means we do not completely know the long term
effects. Do not try to find out. There is a good chance that it does not have the most healthy outcome.
Be nice to each other. Watch your mental health as well. Pro tip: disable both voice and text chat if you feel like you are getting angry.
There is a difference between helpful critique and flaming. Do not flame your teammate. If you get flamed, either just ignore it. But if he calls no info and is only being a prick, just mute him. Do not waste your valuable energy on someone who
cannot even watch their temper.