Might as well share my story here in the hopes that it might be of use to someone else. Apologies for the length.

At the start of summer 2016 my phone screen broke, causing the bottom line on the keyboard to go black. This obviously led to a lot of mistakes which led to a lot of backspacing, and all this backspacing was done with my right thumb. It soon became quite sore, so I tried to even things out a bit, but then the same thing happened to my left thumb. I was solo-travelling up the west coast of the US at this point (I think it started/got very bad in Seattle) and when I made it to my friend in Vancouver I think it may have gotten a bit better from not using my phone as much. When I arrived home I sensibly topped it all off by, on my laptop, typing up every single one of my notes from the previous six years.

It then got so bad I would not want to put away the groceries and even holding a book was sore. The doctor was not particularly helpful, she even just literally Googled stuff in front of me and then printed out one of the pages... But she did prescribe some gel to apply on my hands that also didn't seem to have any effect. Your mileage my absolutely vary here though, but I would reckon that a Physiotherapist would be a better bet than a doctor (although you might as well go to both).

I was incredibly worried that I would not be able to complete the final year left in my degree. From sculpting to programming my hands were crucial to my being. So it was obviously quite distressing when they weren't functioning as intended.

Two years on though and I can say things have dramatically improved. While my hands are still not back to their former glory, they are not holding me back in any way. I finished my degree, got a paper into NIPS, and am now working very hard as the first engineer at Inscribe (YC S18) so there's nothing to fear.

Things I've tried that helped:

Minimizing phone usage as much as possible: If it can be done on a computer instead, do it on a computer.

Taking breaks

Minimizing mouse usage as much as possible: mainly done by using Vimium [0] and other keyboard shortcuts, but doing so is only good if you have an...

Ergonomic keyboard: I use the Microsoft Sculpt Ergonomic Keyboard [1] and find that the keyboard is great, but the mouse doesn't really help that much. A Kinesis keyboard might be even better but I have yet to try one.

A spiky yoga ball thing: Mine looks like [2] and is good for massaging my hands or forearms if they get sore.

Running my hands through the hot & cold taps can be nice the odd time for some relief.

There are also some other great suggestions in the comments

Things that I've tried that were probably not necessary/overkill:

Hot & ice water: I used to spend about and hour or two a day alternately soaking my hands in buckets of ice water and hot water. After I stopped I did not really notice any change, except in the rate I got through podcasts.

Avoiding anything using my hands: for a while I avoided the gym and anything using my hands, and this may have been warranted at the worst period, but after that I found that working out seemed to help a little bit, and even it didn't it's unhealthy not to. Deadlifts are very different from texting so I wouldn't worry too much about that.

Things I haven't tried that may help:

A wrist brace

Wristbands

Other points:

Cold definitely makes it worse: I remember one time in particular during my final year project where I had to program a drone outside in the middle of winter on my unergonomic laptop keyboard. Not fun.

This situation has massively heightened my sense for bad ergonomics. And in doing so, completely changed how I look at the design of technology, and a lot of common assumptions of technology in general. While I used to think the Apple keyboard was beautiful I now only consider its form aesthetic, while its function, and the object as a tool, is far from it. I care much less about a lot of the advancements in phones because I want to use mine as little as possible. And the startup trope of an office of people coding on couches, hunched over their laptops is now almost terrifying.

It's also amazing to note the sheer level of addiction a phone can create. Even though it is painful and I know it is, I still find it hard not to flick through stuff in the morning.

If anyone wants to talk more about this, my email is in my bio.

[0] https://chrome.google.com/webstore/detail/vimium/dbepggeogba...

[1] https://www.microsoft.com/accessories/en-us/products/keyboar...

[2] https://image.dhgate.com/0x0/f2/albu/g5/M00/DB/D9/rBVaI1lklx...

EDIT: Another great way to avoid texting is to send voice messages or even better just call. But obviously these are not always possible.