Ideally, you'll tackle blood stains while they're still wet, which makes them easier to get out. But they're definitely a challenge. This video shows the best way to treat them.
Bowl or sink filled with cold water, bar of soap, stain-removal spray, ammonia, cotton swab, paper towel, laundry detergent
1Wet the stain with cold waterIf the stain is fresh and still wet, soak fabric in cold water immediately.
2Rub with soapRub the stain well with a bar of soap, lathering gently.
Tip: For light-colored fabrics, dab with a hydrogen peroxide, which acts as bleach.
3Re-soak the stain with a pre-treatment stain removerIf the stain has already dried, spray with stain-removal solution. Let it soak in.
4Dab on diluted ammoniaApply a small amount of diluted ammonia to the area with a cotton swab.
5Launder fabricMachine-wash the fabric using an enzyme detergent (most standard laundry soaps are enzyme-based), which breaks down protein stains. Make sure the blood has lifted before putting fabric in the dryer, as the heat will set the stain.