About a year ago I vomited with a small amount of blood in it, and again tonight I puked with blood. What's the most likely caus first time I puked in about a year.

There. There are several possibilities to consider. These include an ulcer, gastroesophageal varicose veins (usually associated with liver disease), a tear in the esophagus (usually only seen with extremely violent vomiting), inflammation or infection of the esophagus, or a problem with your blood clotting system. A tumor of some type might also bleed. You need to be evaluated for this, and will probably need a procedure called endoscopy. Until then, avoid Aspirin (which irritates ulcers, can cause nausea, and thins the blood). If you are on other blood thinners, like Plavix or coumadin, (warfarin) your dose levels may need to be adjusted, but don't stop taking those medicines without seeing your doctor.