How do I hide my scars

I was posting about smt else then remembered that I have to get some blood work done, FUCK I OFC FORGOT THAT FACT, the scars are deep and quite noticeable but it’s on my upper to mid biceps, how do I guarantee that they won’t see it (it’s was hard enough trying to find it from my doctor when testing my blood pressure) please I need tips like ASAP my appointment is soon