How long does it take body to replace blood?

Answer 1

"blood cannot be replaced as you only have 8 pints throughout your whole life."

is obviously a false statement. If you only have 8 pints for your entire life span, how can people donate 1 pint multiple times in your life? You don't just donate until you dry up. If someone could answer how long it takes for the blood to replace, that would be great as I do not know the answer to that question myself. I do, however, know that blood does regenerate.

The fluid component of the blood (plasma) is replaced in approximately 24 hours provided you remember to drink enough water.

The red blood cells are replaced in a few weeks - one study performed recorded an average of 36 days, with a range from 20 to 56 days in the volunteers. Obviously a diet containing iron will help improve recovery time.

*although not a complete answer i can add this, (i am aware this is an old question) haha. On average a properly nourished human body will produce (roughly) 20,000 red blood cells a second, so 1,200,000 a minute and 72 million an hour, taking into account that in one pint there will be trillions of red blood cells, and the body also has to replace red blood cells as they die it will probably take a few days to replace the whole pint, i gave blood yesterday and the guidelines for donating again is not for 3/4 months however i highly doubt it takes any more than 2 weeks to replace the blood, it just means that your body starts producing more red blood cells when you've lost blood and therefore using up more iron, having the possibility of making you anemic.*

Answer 2

It obviously depends upon how much blood is lost. Depending upon your gender it takes either for males a minimum of 12 weeks and for females a minimum of 16 weeks to return to their optimal blood supply. These may seem like lengthy numbers, but these are based upon donating blood upon which a person usually gives about 13% of their blood (usually around a pint, though it depends upon the size of the person). If you have lost enough blood to worry about this, you either have donated, or should be in the hospital. A "minor" wound of sorts may seem to bleed a lot, but a pint is a LOT of blood, odds are you will recover sooner than these numbers for any mundane injury.

The 12 and 16 week numbers are based upon an average person's needed time to have their hemoglobin level return to 135 grams per liter for men and 125 grams per liter for women. Your body, or anyone elses may return to "full capacity" before these times, but these generalized times are a fairly practiced guideline for certainty that you have again returned to your optimal blood capacity and functionality.