Procedure prep
Fasting Before a Mastectomy
A mastectomy removes breast tissue, usually to treat or prevent breast cancer, under general anesthesia. Alongside the standard fasting and medicine checks, there are a few breast-surgery-specific things worth asking about beforehand.
Fasting for this procedure
→ Get your exact fasting times with the calculator
Medicines to check
- Blood thinners (aspirin, clopidogrel, warfarin, Eliquis, Xarelto) — see medications to stop.
- Hormone therapy (tamoxifen, letrozole) — tamoxifen slightly raises clot risk, so ask whether to pause it around surgery.
- Diabetes medicines & insulin need a fasting-day plan. See diabetes tablets.
- Blood pressure medicines — confirm which to take with a sip of water.
- Tell your team about any recent chemotherapy and its timing.
When this surgery may be delayed
- Fever, a new cough/cold, or a chest infection
- A skin infection or open sore on the breast or armpit area
- Low blood counts after recent chemotherapy (your team will check)
- Very high blood pressure or blood sugar
- You ate or drank outside your fasting window
Reports & documents to carry
- Photo ID and your insurance or hospital paperwork
- A current list of all your medicines, doses, and allergies
- Mammogram, ultrasound, MRI, and biopsy reports if you have copies
- Your chemotherapy or oncology schedule if relevant
- A front-opening top and a soft supportive bra, plus a ride home
What to ask your anesthesia team
- Will I have reconstruction at the same time, or later?
- Will you check the lymph nodes (sentinel node biopsy), and what does that involve?
- Will I go home with a drain, and how is it looked after?
- Should I pause my tamoxifen or other hormone tablets?
- How long is the stay, and when can I use the arm normally?
Your prep checklist
Tick things off as you sort them — saved on this device only, nothing is sent anywhere.
A general guide — your hospital's own instructions always come first.
Frequently asked questions
Will I wake up with a drain after a mastectomy?
Often yes. A small drain is commonly placed to remove fluid that collects after breast or armpit surgery, and you may go home with it for several days. Your team or a nurse will show you how to empty and measure it, and arrange its removal — it's routine and not as daunting as it sounds.
Should I stop tamoxifen before surgery?
Tamoxifen slightly increases the risk of blood clots, so some teams pause it around bigger operations while others continue it. There isn't a single rule, so ask your surgeon and oncologist what they advise in your case rather than stopping it yourself.
What is a sentinel node biopsy and why might I need it?
It's a way of checking whether breast cancer has spread to the lymph nodes in the armpit, by removing the first one or two nodes that drain the breast. It often involves a small injection of dye or a tracer beforehand. Your surgeon will explain whether it's part of your operation.