Fasting and blood donation, can you donate on an empty

No, this one is a firm stop, for your safety or the patient’s. No, do not donate fasting. Eat a proper meal first; an empty stomach multiplies faint risk. ## The short answer Donation drops blood volume; fasting drops blood sugar. Together they are a faint waiting to happen. Religious fasting with a permitted pre-dawn meal, donate after that meal; total fasts, choose another day. ## At the screening desk Tell the staff: Staff always ask when you last ate, answer honestly. That conversation is confidential and takes a minute, it exists so the medical officer can clear you safely on the day. Everyone meets the same basics: age 18,65, weight 50 kg+, haemoglobin on target, feeling well today. Men donate every 3 months, women every 4, the rest rules, simply. Not sure about your case? Try the Can I donate? checker or read who can donate and the deferral list in plain words. Still weighing it? Is blood donation safe? and the honest side-effects list are straight answers, not brochure talk. ## The one line that matters The medical officer at the centre makes the final call on the day, with your name, your file and your actual reading in front of them. Use this page to walk in informed, not to overrule anyone. Related: what to eat before donation