Direct pressure will stop most external bleeding, and is the most important initial first aid.
Blood loss can cause bruises, which usually result from a blow or a fall. They are dark, discolored areas on the skin. Apply a cool compress to the area as soon as possible to reduce swelling. Wrap the ice in a towel and place the towel over the injury. Do not place ice directly on the skin.
Serious injuries don't always bleed heavily, and some relatively minor injuries (for example, scalp wounds) can bleed profusely. People who take blood-thinning medication or who have a bleeding disorder, such as hemophilia, may bleed excessively and quickly because their blood cannot clot properly. Bleeding in such people requires immediate medical attention.
Always wash your hands before (if possible) and after giving first aid to someone who is bleeding to avoid infections. Try to use latex gloves when treating a bleeding victim. Latex gloves should be in every first aid kit.
People allergic to latex can use a non-latex, synthetic glove. Viral hepatitis can be transmitted by skin contact with infected blood, and HIV can be contracted if infected blood gets into an open wound -- even a small one.
Although puncture wounds usually don't bleed very much, they carry a high risk of infection. Seek medical care to prevent tetanus or other infection.
Abdominal wounds can be very serious because of the possibility of severe internal bleeding, which may not be obvious from looking at a person, but which may result in shock.
Seek medical care immediately for any penetrating abdominal wound. If organs are showing through the wound, do not try to push them back into the abdomen unless they slide back in without your assistance. Cover the injury with a moistened cloth or bandage, and do not apply more than very gentle pressure to stop the bleeding.
Always seek emergency assistance if internal bleeding is suspected. This can rapidly become life-threatening. Immediate medical intervention may be needed. This can range from medications and intravenous fluids, to use of an internal scope (endoscope), to surgery.
Seek emergency assistance for severe bleeding, loss of a body part, or any serious head injury.
