I Know That Smoking Crystal Meth Is Very Harmful For

I know that smoking crystal meth is very harmful for you. Unfortunately I am a daily user and have been for over 10 years. My question to you is; my doctor found a lump on my thyroid and I'm scheduled to have a biopsy. They said not to take any type of pain medicine 7 days before my appointment. And I can only assume this would mean why side activity. My problem is I cannot go even 1 day with out it and I know the answer everyone will want to give me is well stop doing it but this is not a choice for me right now. So if I smoke before this biopsy not the day of but the days prior should I honestly run into complications? If so, how and could it be life threatening???