We talk a lot about the need to drink water before and after your blood donation, and there’s a reason: Hydration is good.
Water is essential to just about every function in your body, including circulating your blood, which is around 80% water. A typical whole blood donation is half a liter (about a pint), so you’re losing water from your body in a short amount of time when you give.
Water and blood donation
Here are three good reasons to make sure you’re properly hydrated when you’re giving blood:
- It makes it easier for your tech to find a vein to start your donation. Hydrated veins in your arm are easier to find.
- Your donation will go more quickly – water makes everything flow better.
- You’re less likely to feel light-headed while giving or afterwards, since reducing the volume of your blood can cause your blood pressure or heart rate to drop temporarily. Having a bottle of water (16.9-ounces) right before donation can help reduce your risk of feeling lightheaded.
After your donation
As soon you’re done giving blood, your body begins to replace that lost water, so all the hydration in your body will go toward replacing it. Your body needs to be ready with extra water when that happens.
Also, it’s suggested you stay away from anything with caffeine or alcohol following your donation because they both can lead to dehydration – the exact opposite of what you need.
How much water?
Current guidelines have boiled down the formula for how much water you need in a typical day:
- Find out your weight.
- Divide your weight in half.
- That number is how many ounces of water you should drink in a day when you’re not doing anything strenuous.
So, if you weigh 200 pounds, you need to drink 100 ounces of water on a typical day, more if you’re working out.
How do you measure?
- A basic tumbler holds 20 ounces
- Bottled water typically comes in two sizes: 16.9 ounces and 20 ounces
- Canned beverages usually are 12 ounces
- A reminder of the U.S. system for liquid measurement:
- A cup is eight ounces
- A pint is 16 ounces
- A quart is 32 ounces
