sissyjanvi_ it's not a "disease." However, if you cross dressing for sexual gratification or high and it's affecting your quality of life or if you are putting yourself or others in dangerous situations over it then it's a paraphilia. It depends. Going by your username I have some doubts what you are seeking here. Is it validation of a kink or something else? No, I'm not going to kink shame you, I'm sex-positive. I'm just wondering what you are looking for, what guidance do you need?
You either get sexual high from feminization, resonate with the opposite gender and find comfort in dressing up as you could be gender non-conforming and cross-dressing gives you an outlet to express yourself, or may even have underlying gender dysphoria that needs a looking into. There is a bit of a spectrum when it comes to CDs. That's why i don't immediately denounce CDs as perverts.
If you have no dysphoria with your gender assigned at birth, then do what makes you feel happy and enjoy dressing up without worrying about logistics of it. No treatments or life changes required. Connect with like minded people and you are good to go.
Just keep in mind that this is primarily a transgender support forum which may or may not be helpful to you but we have CDs, infact, more CDs than transgender individuals. You'll probably make connections that'll help you balance your CD life.
As long as you are not harming yourself or others, it's perfectly okay. 😌