Blood constantly flows through your veins and arteries providing your body with oxygen, nutrients and waste removal. We depend on it to ward off serious health complications, and losing too much from injury or major surgery can be fatal. Bank on these facts to get your juices flowing.

7% of your weight is made up of blood.

How many major blood groups are there? 4 — A, B, AB and O

38,000 — Blood donations needed every day in the U.S. to help accident victims, patients getting surgery and those with cancer and blood disorders.

10 — Approximate pints of blood in your body. When you donate blood, you're giving about 1 pint in 8 to 10 minutes.

1,500 milligrams — Amount of salt you should limit yourself to each day to dramatically lower your blood pressure.

.08% — Four beers, shots of liquor or glasses of wine will raise a 180-pound man’s blood alcohol concentration to this percent, which is considered in most states to be over the legal driving limit.

— Glenda Fauntleroy