Blood Center

What is Blood?

Blood is a living tissue composed of blood cells suspended in plasma.

The cellular elements, red blood cells, white blood cells and platelets -- make up about 45% of the volume of whole blood. Plasma, which is 92% water, makes up the remaining 55%.

Blood accounts for approximately 7% of a person's weight. An average sized man has about 12 pints of blood, and an average sized woman has about 9 pints. When you donate blood, your body immediately begins replacing the donated blood volume, so you can safely donate as often as 6 times a year.

Blood Types in the U.S.

 

Blood Type Breakdown

Blood Type How Many Have It
Frequency
O +   1 person in 3
37.4%
O -   1 person in 15
6.6%
A +   1 person in 3
35.7%
A -   1 person in 16
6.3%
B +   1 person in 12
8.5%
B -   1 person in 67
1.5%
AB +   1 person in 29
3.4%
AB -   1 person in 167
.6%

 

Blood Compatability Chart

  YOU CAN RECEIVE TYPE
I
F

Y
O
U

A
R
E

T
Y
P
E
  O+ O- A+ A- B+ B- AB+ AB-
O+ * *            
O-   *            
A+ * * * *        
A-   *   *        
B+ * *     * *    
B-   *       *    
AB+ * * * * * * * *
AB-   *   *   *   *

Stanford Medicine Resources:

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