Anemia is a medical condition where your blood doesn't have enough healthy red blood cells to carry oxygen throughout your body. Red blood cells are like tiny delivery trucks that transport oxygen from your lungs to every part of your body: your muscles, your brain, your organs. When you have anemia, you don't have enough of these delivery trucks, so your body doesn't get all the oxygen it needs.

People with anemia often feel tired and weak because their muscles and brain aren't getting enough oxygen to work at full power. They might look pale, feel dizzy, or get short of breath easily, even from activities that normally wouldn't tire them out. Imagine trying to run a race while breathing through a thin straw: that's similar to how anemia can make your body feel.

Anemia has many causes. Sometimes people don't eat enough iron-rich foods like meat, beans, or leafy green vegetables, and iron is essential for making healthy red blood cells. Other times, the body loses blood through injury or illness. Some people inherit types of anemia, like sickle cell anemia, where their red blood cells are shaped differently and can't carry oxygen properly.

Doctors can detect anemia with a simple blood test and usually treat it successfully with better nutrition, iron supplements, or other medicines, depending on the cause.