The U.S. blood supply has reached crisis levels, prompting the American Red Cross and the Surgeon General's Office to urge people to donate.

Why it matters: A prolonged blood shortage could delay surgeries, trauma care and other treatments that depend on timely blood transfusions.

• The Red Cross says it has "less than a one-day national supply of type O positive blood," which is the most commonly transfused blood type. Due to the shortage, the organization is limiting distribution of type O blood to hospitals.

Driving the news: Blood donations fell to a four-year summer low in 2026, the Red Cross said on Monday.

• Current supply is not keeping up with the demand for blood, which increases during the summer, the Red Cross says.
• The Red Cross attributes the low turnout of donations to extreme heat, bad air quality and "widespread foodborne illnesses" hitting the country.

What they're saying: "Every donation has the potential to help save lives, and we urgently need everyone who is eligible to make an appointment to give blood as soon as possible," Chris Hrouda, president of Red Cross Biomedical Services, said in a press release.

Flashback: This is only the second national blood supply crisis, according to the Red Cross.

• The last time was in January 2022 when COVID, winter storms and staffing challenges disrupted the nation's blood supply.
• In 2024, the Red Cross said it faced an "emergency blood shortage," though stopped short of declaring it a "crisis."

How to donate blood

How it works: You can visit a nearby blood collection location to make an appointment. You can also contact the following:

• Association for the Advancement of Blood and Biotherapies (website) — 301.907.6977
• America's Blood Centers (website) — 202.393.5725
• American Red Cross says eligible donors can book an appointment on their website. (RedCrossBlood.org) or call 1-800-RED-CROSS (1.800.733.2767).

Zoom in: Find a Red Cross or Versiti blood drive near you.

Perks and rewards for blood donation

The American Red Cross is offering incentives for donating.

• Anyone who donates by July 31 receives a Fandango movie ticket, which will be worth up to $15.
• The Red Cross is also offering a $20 Amazon gift card to anyone who donates in August.

Go deeper: A pro donor's guide to giving blood