Blood Donation Requirements and Eligibility: Complete Guide

Who Can Donate Blood? The Basic Requirements

Blood donation saves lives — approximately 1 in 4 people will need a transfusion at some point — but the supply depends entirely on voluntary donors. Only about 5% of eligible Americans donate blood each year, yet over 80% of all blood used in transfusions comes from repeat donors.

The basic eligibility requirements are straightforward, but many specific conditions, medications, and circumstances create temporary or permanent deferrals. Understanding these rules helps you know whether you’re eligible and when to try again if you’re not.

The three fundamental requirements to donate whole blood are:

1. Age: At least 17 years old (16 with parental consent in some states; no upper age limit)
2. Weight: At least 110 pounds (50 kg)
3. Health: In good general health on the day of donation

These are the starting point. Additional screening happens at the donation center on the day you arrive.

What Health Checks Happen on Donation Day?

Before every donation, staff will:

• Check your temperature — Must be below 99.6°F (37.5°C). A temperature at or above this threshold results in a temporary deferral
• Measure your blood pressure and pulse — Pulse must be between 50 and 100 beats per minute; blood pressure checked for safety
• Test your hemoglobin (iron level) — A finger-stick blood test measures your hemoglobin. Women need at least 12.5 g/dL; men need at least 13.0 g/dL. Low hemoglobin means a temporary deferral until levels recover
• Review your health history questionnaire — Covers recent illnesses, medications, travel, and behaviors that could affect blood safety

These checks protect both the donor and the recipient.

What Medical Conditions Affect Eligibility?

Many medical conditions cause a temporary deferral rather than a permanent one. Common examples:

Temporary deferrals:

• Cold, flu, or fever — wait until symptoms have resolved and you’ve felt well for at least 48 hours
• Dental work — routine cleaning or filling: 24–72 hours. Extractions require a 72-hour wait
• Minor infections or antibiotics — wait until the course of antibiotics is complete and you feel well
• Pregnancy — defer during pregnancy; most women can donate 6 weeks after delivery
• Recent vaccination — varies by vaccine type; live vaccines (MMR, chickenpox) typically require 4 weeks

Conditions requiring medical review:

• Controlled high blood pressure — eligible if well-managed and feeling well
• Controlled diabetes — eligible if managed by diet or oral medication; insulin use requires specific evaluation
• Heart disease — some cardiac patients may donate if condition is stable and physician approves
• Asthma — eligible if well-controlled and no active symptoms

Permanent deferrals (cannot donate at all):

• HIV positive
• Hepatitis B or C (ever)
• Intravenous drug use (ever)
• History of certain cancers (leukemia, lymphoma; solid tumor cancers evaluated case by case)
• Creutzfeldt-Jakob disease risk (extended residence in UK 1980–1996 or other CJD-risk criteria)

How Do Medications Affect Eligibility?

Most common medications do not disqualify you from donating if the underlying condition is under control. However, some medications require waiting periods:

Always bring a list of your current medications when you donate. Staff will review them with you. Many medications have no restriction at all.

What Travel History Affects Eligibility?

Travel to certain regions creates a temporary or permanent deferral due to disease exposure risks:

Malaria:

• Travel to a malaria-endemic area: 3-month deferral after return
• Former residents of malaria-endemic countries (who lived there for 5+ years): 3-year deferral after departure

Variant CJD (mad cow disease):

• Spending 3 or more months total in the United Kingdom between 1980 and 1996: permanent deferral in most U.S. blood centers
• Time spent in other European countries with elevated vCJD risk: evaluated by cumulative duration

Other travel risks:

• Recent travel to active Zika outbreak regions: temporary deferral (typically 4 weeks after return, or 8 weeks for those who may have been exposed through sexual contact)

If you’re unsure whether your travel history affects eligibility, the blood center will assess it during your health history review.

What Behavioral History Is Screened For?

The donor questionnaire asks about behaviors that elevate the risk of bloodborne infection:

• Injection drug use (ever): Permanent deferral
• Sex with a new partner: Some centers may ask about recent new partners in combination with other risk factors
• Receipt of money or drugs for sex (ever): Permanent deferral
• Incarceration of 72 hours or more: 12-month deferral

The U.S. donor screening system operates on an honor system — donors self-report. Blood centers also cross-reference against deferred donor registries. However, accurate self-disclosure remains the first and most important line of defense in blood safety.

How Often Can You Donate Different Blood Components?

The frequency of donation varies significantly by blood component type:

After whole blood donation, your red blood cell count, plasma volume, and iron stores need time to rebuild. Donating too frequently — or giving double red cells (where two units’ worth of red cells are collected in a single session) — increases the risk of anemia and fatigue.

Iron depletion is a real concern for frequent whole blood donors, particularly women. Some centers recommend iron supplementation for regular donors. Eating iron-rich foods in the days before donation helps maintain your hemoglobin.

What Happens If You’re Deferred?

A deferral is not a rejection — it’s a safety measure that protects both you and recipients. Most deferrals are temporary.

If you’re deferred:

• Ask what specifically caused the deferral
• Ask when you can come back and try again
• Ask whether there’s anything you should do in the interim

If you are permanently deferred but believe you were assessed incorrectly, you can ask the blood center about their re-evaluation or appeals process. Eligibility criteria are periodically updated as science evolves — some deferrals that were once permanent have been changed to time-limited policies.

Can Children or Teenagers Donate?

Minors can donate in limited circumstances:

• Autologous donation (for yourself): Children over 65 pounds may donate their own blood for a planned surgery, with physician order and parental consent
• Regular blood donation: Minimum age is 17 in most states; 16 with parental permission in some

Age is not a concern at the upper end — there is no maximum age for blood donation as long as the donor is in good health. Older adults who regularly pass their health screening can and do donate throughout their lives.

What Makes Someone a Valuable Repeat Donor?

Blood centers depend heavily on repeat donors for supply stability and safety. First-time donors who never return represent a higher risk category — research shows that 95% of HIV and hepatitis-positive donations come from first-time donors who did not return within 90 days. Repeat donors have been tested multiple times and have established safety records.

If you are eligible and able, donating regularly — even twice a year — meaningfully contributes to a supply that serves millions of patients annually. Blood has a short shelf life: red cells expire in 42 days, platelets in just 5 days. Demand is continuous.

For information about donating your own blood before surgery, see Autologous Blood Donation.