White Blood Cells

White blood cells are part of your immune system. They are like tiny soldiers that protect your body from germs. Whenever you get sick, white blood cells rush in to fight the invaders.

How They Protect You

White blood cells travel through your blood looking for germs. When they find bacteria or viruses, they attack and destroy them. Some white blood cells eat the germs. Others make special weapons called antibodies.

Antibodies stick to germs and mark them for destruction. Your body remembers the germs it has fought before, so it can fight them faster next time.

Types of White Blood Cells

There are several types of white blood cells. Some are fast fighters that arrive first at an infection. Others are specialists that create antibodies. Each type has a different role.

When you are sick, your body makes extra white blood cells. That is why a doctor might check your blood to see if you have an infection.

Fun Facts

• White blood cells make up only about one percent of your blood.
• Some white blood cells can live for years and remember old germs.
• A healthy person has about 4,000 to 11,000 white blood cells in a single drop of blood.

Did You Know?

White blood cells can squeeze through the walls of blood vessels to reach germs in other parts of your body, like tiny superheroes passing through walls!