Who Can Donate Blood: A Practical Guide
Updated May 2026
Editorial position
This page summarises eligibility for blood donation in the US and UK based on current published criteria. Eligibility lists change regularly. For your specific situation, check the official Red Cross or NHSBT eligibility tools (linked throughout) or call the donation centre. Final eligibility is determined at the donation visit by the donor health check, not by self-assessment online.
The basic eligibility tests
All blood donor programmes use a layered screening: a health questionnaire to capture history and recent exposures, a brief health check (blood pressure, pulse, haemoglobin), and the donation itself, with bloodborne virus testing performed on the collected unit before it is released for transfusion.
The questionnaire identifies temporary deferrals (recent travel, recent tattoo, recent specific medications, recent vaccinations) and permanent deferrals (specific cancers, specific neurological conditions, specific previous transfusion exposures). The health check at the visit confirms the donor is safe to give that day. The post-collection testing protects recipients from infections that the questionnaire and health check cannot identify.
The detailed eligibility criteria are published by the American Red Cross eligibility page and the NHSBT who can give blood page. Both are regularly updated; this page summarises the major points but is not a substitute for the official source.
Age and weight
US: 17 years old (16 with parental consent in many states). No upper age limit if the donor is in good health and meets the haemoglobin and other criteria. Minimum weight is 110 lb (50 kg).
UK: 17 years old at minimum. The previous upper limit of 65 for new donors was removed in 2018; existing donors can continue past 70 with annual GP confirmation of good health. Minimum weight is 7 stone 12 lb (50 kg) and maximum is 25 stone (158 kg).
See our dedicated age and weight restrictions page for more on the rationale and the specific cut-offs.
Health and current illness
You should feel well on the day of donation. Active infection (cold, flu, fever, throat infection) defers donation until you have fully recovered, typically 7 to 14 days. COVID-19 infection defers donation for 14 days after symptoms resolve in the UK and 10 days in the US. The donor health check will defer you on the day if you appear unwell or have low haemoglobin.
Common chronic conditions that are not deferrals when stable: well-controlled hypertension, well-controlled type 2 diabetes (oral medications only in the US, including insulin in the UK with stable disease), well-controlled asthma, treated thyroid conditions on stable replacement, eczema and psoriasis (avoiding active skin lesions at the puncture site), and most allergies.
Conditions that are typically deferrals: insulin-treated diabetes (US, varies; UK accepts on stable regimen), uncontrolled hypertension, recent significant cardiovascular event (heart attack, stroke, transient ischaemic attack - both jurisdictions defer for at least 6 months and many indefinitely), recent major surgery, active cancer treatment, autoimmune conditions on immunosuppressants. The detailed lists are at the official Red Cross and NHSBT pages linked above.
Tattoos, piercings, and acupuncture
UK: 4 months after a tattoo, body piercing, semi-permanent makeup, or non-sterile acupuncture (acupuncture by an NHS practitioner or registered acupuncturist using sterile equipment is not a deferral).
US: tattoos applied at a state-regulated facility using sterile single-use needles are not a deferral. Tattoos at unregulated facilities defer for 3 months. Piercings have similar rules. Some states regulate body piercing differently from tattooing.
The deferral exists to mitigate risk of bloodborne virus transmission (HBV, HCV, HIV) during the period when the infection is present in the donor but not yet detectable by screening tests (the eclipse period). Modern PCR-based screening narrows this window but does not eliminate it.
Recent travel
Travel to malaria-endemic areas defers donation for 3 months after return. Both the Red Cross and NHSBT publish current country lists, which include most of sub-Saharan Africa, parts of South Asia, much of Central and South America, parts of Southeast Asia, and parts of Oceania. The 3 month interval covers the typical incubation of Plasmodium falciparum and similar species.
Travel to areas with active outbreaks of dengue, Zika, chikungunya, or other arboviruses may add specific deferrals; the lists change with current public health advice. Travel to specific regions (parts of West Africa for HTLV, parts of UK or France for vCJD historically) may carry longer or permanent deferrals depending on the donor's residence history.
Always declare travel honestly on the donor questionnaire. The deferral is reversible (most are time-limited) and the alternative (transmitting an infection to a recipient) is not.
Sexual history and bloodborne risk
Both the US and UK have moved away from blanket categorical deferrals for men who have sex with men toward individual risk-based assessment. The FDA May 2023 announcement shifted US donor screening to individual risk questions: new partners in the last 3 months, anal sex with a new partner. The UK NHSBT changes from June 2021 made similar individual-question changes. All donors regardless of gender or sexual orientation are asked the same risk questions.
People living with HIV, HBV, or HCV cannot donate. People taking pre-exposure prophylaxis (PrEP) are deferred for a defined period after stopping (3 months in the US for oral PrEP, 2 years for injectable cabotegravir; UK guidance is similar in principle but specific intervals differ).
History of sex work or commercial sex work is a deferral in both jurisdictions, with time intervals varying.
Pregnancy and breastfeeding
Pregnancy is a deferral. After delivery the deferral runs to 6 weeks (US) or 6 months (UK). Breastfeeding is not a barrier in the US once the postpartum interval has passed. UK guidance allows breastfeeding mothers to donate but recommends waiting until the baby is being introduced to solids.
The deferral exists primarily to protect the mother from iron depletion (pregnancy and lactation deplete iron stores) and to ensure she is fully recovered before giving an additional 470 mL of blood. It is not because anything in the breast milk would harm the baby.
Some women find that after pregnancy they need additional iron supplementation to maintain donation eligibility. Iron is checked at each donation visit (haemoglobin); persistently low haemoglobin should prompt a discussion with your GP.
If you are deferred
A deferral is not a rejection. Most are time-limited (3 to 12 months) and reversible. The donor centre will tell you the duration and the reason. After the deferral period, you can return and donate normally. Some deferrals (specific cancers, specific previous transfusion histories) are permanent.
If you are deferred for low haemoglobin, increase dietary iron (red meat, leafy greens, fortified cereals, lentils) and consider an oral iron supplement; recheck in 8 to 12 weeks. If you are deferred for high blood pressure, see your GP; once treated and stable, you can return. The Red Cross and NHSBT both want as many donors as possible to come back, and the deferral conversation is meant to facilitate that.