Hello sir ;
welcome to HealthcareMagic
At 25 yrs you are young and the habits you are having are like giving invitation to many diseases in future.Presently you are taking your chances and if you do not have any problem you don't need a medical check up immediately but if things change or you get any symptom then may be you will require it.The better option is to discontinue smoking
and even rum if it is possible for you so that you remain healthy and you know HEALTH is WEALTH like every body says.If you do it right now your body can repair most of the damage caused and in later life you will be almost free of the side effects of these habits so earlier is better.
Hope the answer is helpful and not offensive.