What are the causes of wrist pain and treatments available?

[RajuV07]

I am a 21 y/o male. I have been feeling pain in my radial side of the wrist(Left hand) especially when I press my hand against the wall and typing on mobile. A bony bump is also developed which was not there before, this bone sometimes becomes less pronounced and sometimes more. If I press this bone I feel pain(not severe).
This pain alternate between my right and left wrists. A bony bump was also there in my right wrist two weeks ago then it gradually became less painful and less noticeable.

[CHIN_C]

This article outlines a clinical approach to diagnosing wrist pain:
https://www.aafp.org/afp/2005/1101/p1753.html
Please refer to Table 3 for specific maneuvers.

[CHIN_C]

Pain in radial side of wrist in distribution of median nerve, exacerbated by typing and pressing hand against wall (reverse Phalen's test), is suspicious for carpel tunnel syndrome. The tiny bumps in your wrist may be ganglion cysts, which can be confirmed with US or MRI. If you are convinced they are bony, consider radiographs to rule out osseous abnormalities.

[Paxiled]

Most likely you're just noticing something that has been like that all along.  It's also probably caused by the way you use your cell phone, as this is a common problem.  But to get a diagnosis of something that might have happened to it other than overuse injuries or poor posture, you have to see a specialist who can do that.  Try not typing on your cell phone for a couple weeks with that hand and see if the pain goes away.