A blood spot in your egg is a tiny ruptured blood vessel, not a sign that anything is wrong with the egg. It happens naturally during egg formation and is completely safe to eat. Roughly 2 to 4 percent of all eggs contain a blood spot or meat spot, so while it looks alarming, it’s one of the most common quirks in egg production.
How Blood Spots Form
When a hen ovulates, the egg yolk is released from a sac in her ovary. That sac has a narrow line called the stigma, a strip with no blood vessels where the rupture is supposed to happen cleanly. If the sac tears slightly off that line, a small blood vessel breaks open and leaks a tiny amount of blood onto the yolk. That blood gets sealed inside as the egg continues forming around it.
Less commonly, a blood vessel in the oviduct (the tube the egg travels through on its way out) can rupture during formation. In that case, the spot may appear in the egg white rather than on the yolk. Either way, the mechanism is the same: a minor vascular accident during a process that happens every 24 to 26 hours in a laying hen.
Blood Spots vs. Meat Spots
You might also crack open an egg and find a brownish or tan speck that doesn’t quite look like blood. These are meat spots, which are small pieces of tissue from the hen’s reproductive tract that broke off and got incorporated into the egg. They’re different from blood spots in composition but equally harmless. Both are considered normal occurrences by the USDA and have no impact on egg safety or quality.
It Does Not Mean the Egg Is Fertilized
One of the most persistent misunderstandings is that a blood spot means the egg was fertilized or contains an embryo. It doesn’t. Fertilization leaves a completely different marker: a small white disc on the surface of the yolk called the blastodisc. In an unfertilized egg, this disc is a tiny, irregular white clump. In a fertilized egg, it’s noticeably larger, round, and composed of tens of thousands of cells. A blood spot has nothing to do with this process. It’s just a broken blood vessel.
Why Some Eggs Have Them More Often
Several factors influence how frequently blood spots show up. Genetics plays a role. Brown egg layers tend to produce blood spots at a slightly higher rate than white egg layers. The hen’s age, activity level, and overall vitamin balance also matter. Research dating back decades found that hens fed diets low in vitamin A produced eggs with noticeably more small blood spots. Low vitamin K levels, linked to reduced alfalfa in feed, have also been associated with higher incidence.
If you raise backyard chickens and notice blood spots appearing frequently, diet quality is one of the first things worth checking.
Why You See Them Despite Commercial Screening
Commercial egg producers use a process called candling, where a bright light shines through each egg to reveal internal defects. Eggs with visible blood spots are pulled from the supply. But the system isn’t perfect. Traditional candling catches blood spots at a rate that varies wildly, from as low as 20 percent to as high as 90 percent depending on conditions.
The biggest factor is shell color. White eggs are relatively transparent under light, making blood spots easy to detect. Brown eggs are a different story. The brown pigment in the shell absorbs light at almost the same wavelength as the hemoglobin in blood, which makes it extremely difficult for candling equipment to distinguish a blood spot from the shell itself. One study found that even advanced detection methods only caught about 85 percent of blood spots in brown-shell eggs using traditional techniques. Newer spectroscopy-based systems have pushed accuracy above 95 percent, but no method catches every single one.
This is why you’re more likely to find a blood spot in a brown egg than a white one. It’s not just that brown egg layers produce them more often. It’s also that the screening process misses them more often.
Are They Safe to Eat?
Yes. The USDA states plainly that small blood or meat spots are rare but normal and pose no impact on egg safety or quality. You can cook and eat the egg as you normally would. If the spot bothers you visually, you can scoop it out with the tip of a knife or spoon before cooking. It won’t change the taste or nutritional value of the egg either way.