Human A&P question

[Carrie12345]

A friend of mine asked (what I think is) an interesting question.

 

Someone with a known health problem is to keep a look out for extreme overnight weight gain from edema.

That person wakes up one day to a 20lb+ weight gain.

 

We understand the whole retention of fluids in tissue aspect, but the question is, how is the mass/weight accounted for? The person did not take in 20lbs of mass to be retained (or changed to something else.) How then does the body create those 20lbs without taking in an equivalent of some sort?

 

I found a few mentions of change in blood flow, but I don't have a high enough level of understanding to figure out how that creates energy/mass/weight.

 

Can any of you medical people help some laywomen?

[RoughCollie]

Water is your body's principal chemical component and makes up about 60 percent of your body weight.

 

Edema occurs when tiny blood vessels in your body (capillaries) leak fluid and the fluid builds up in surrounding tissues, leading to swelling.

 

http://www.mayoclinic.org/diseases-conditions/edema/basics/causes/con-20033037

 

 

PS  I am not a medical professional, so this is a simple answer.

[Carrie12345]

Water is your body's principal chemical component and makes up about 60 percent of your body weight.

 

Edema occurs when tiny blood vessels in your body (capillaries) leak fluid and the fluid builds up in surrounding tissues, leading to swelling.

 

http://www.mayoclinic.org/diseases-conditions/edema/basics/causes/con-20033037

 

 

PS  I am not a medical professional, so this is a simple answer.

 

Well, that's the part we understand. :thumbup1:

But knowing, say, that the body "makes" 20lbs of fat by retaining excess calories over time... where does the body get the mass/energy to "make" 20lbs of excess fluid in a 12 hour period?

[kroe1]

It is mostly derived from mass intake (fluids consumed) which is then not secreted out by the kidneys because the fluid was no longer contained within the vascular system that passes out through the kidneys. That is the bulk of the weight gain anyway. The rest is more complicated.

[Chris in VA]

 I have never heard of it happening overnight--and this is just a guess, but...

 

The water is retained which is usually shed. We shed far more than we'd probably figure. A gallon of water weighs 8 lbs--think (to be gross) of all you pee during the day.

 

Water comes from lots of things--fat, for example, contains water. So the natural fat you would burn during the course of burning the calories you need just to stay alive for a day would produce water. In edema, most of the water would be retained. The cells contain water, etc. Not to mention what we consume--as Minnie obviously beat me to! lol

 

ETA--Oh, duh--I reread your question and finally get it.

 

I think it also has to do with when we weigh ourselves--we think we weigh the same all day, but of course, right before we urinate, we weigh more. If we don't pee, then we gain, so to speak. A lot of foods contain moisture/water. I would imagine that is where it comes from.

[Dmmetler]

Pre-eclampsia? I can personally attest that it is possible to gain 20 lbs overnight with severe PE. One thing I remember was feeling parched and nauseous the day that it hit, so I suspect that I did consume more fluids as well. Add that kidney function was very low, and the sum total was turning into the Pillsbury doughboy.

[gardenmom5]

It is mostly derived from mass intake (fluids consumed) which is then not secreted out by the kidneys because the fluid was no longer contained within the vascular system that passes out through the kidneys. That is the bulk of the weight gain anyway. The rest is more complicated.

 

except since 20 lbs is equivalent (roughly) to 2 1/2 GALLONS of water - where did it come from in that time period?  they didn't eat or drink that amount of weight in that time.

[TCB]

I realize that someone up the thread gained 20 lbs in a day, but I don't think I've known that to happen in my experience, or if it has very rarely. I work in ICU and people can gain a lot of water weight when they are sick, but in my experience it is mostly because of fluid etc going in and not being excreted, but instead going into the tissue. Just for reference - 1 liter of fluid weighs 1 kg approx. I guess you could gain approx 10 kgs in a day but you would need to have a lot going in and very little if any coming out. When we send people home we tell them to be concerned about a 3lb weight gain in 1 day.

[Catherine]

The water comes from intake of fluids and from metabolism of things we take in. So it's from what goes into your mouth. As such, 20 pounds in a day is pretty unlikely, but I suppose it's not impossible. A gallon of water weighs 8 pounds. If a person who is monitoring their weights daily and recording them before eating and after urinating in the morning, there really should not be much variation (more than 2-3 pounds per day MAX) even in someone with impaired kidney or heart function.

[MyThreeSons]

Well, what about a tumor? They can get very massive, and somehow seem to grow "out of nowhere". 

 

I know that when my uncle was dying of Mesothelioma, he would gain massive amount of weight fairly quickly. It turned out to be a combination of malignant tumors and fluid build up in his abdominal cavity. They would insert a syringe and draw off a huge amount of fluid every week or so. Before they did it each time, he would look like he was several months pregnant. And he wasn't eating much. 

[regentrude]

The body can not create 20lbs. The body can not create any mass. Nothing can create mass, it is impossible.

The body can retain mass that has been taken in, instead of excreting it.

Since the person would not be taking in 20lbs during one day (ETA: Under normal circumstances*), the person also can not suddenly be retaining 20 lbs overnight. Not.possible.

 

*Extreme unusual situations, as explained by the next poster, are possible but very rare.

And water taken in through IV fluids is still taken in, not "created".

[regentrude]

Well, what about a tumor? They can get very massive, and somehow seem to grow "out of nowhere".

 

Any mass the tumor gains must come from somewhere - either surrounding tissue, or intake of material. The mass in the tumor can not be created by the body. Any chemical reaction has to obey the conservation of mass... unless you have a nuclear reaction where you convert mass to and from energy. Not happening in the human body.

 

[kroe1]

...

Since the person would not be taking in 20lbs during one day, the person also can not suddenly be retaining 20 lbs overnight. Not.possible.

It is actually possible, I have seen it a time or two, but it was extremely bizarre circumstances. Once was a aortic aneurysm repair and during surgery massive amounts of blood and fluid was required because of complications including acute renal failure. This person was actually out fishing a week later.

 

I also saw it once in an obese diabetic with renal failure requiring dialysis. She ate a couple of Totinos pizzas. The added salt and glucose level caused her to have massive thirst before coming to the ER with shortness of breath.

 

Finally, I have seen cirrhosis patients before who claim 10 to 20 lb weight gains overnight. I do not know how accurate that is, however. House scales may have a 1 to 2 lb variance.

 

About the most one could gain from eating solids only would be about 2 lbs. and that would require eating almost constantly. It is fluid buildup that is the culprit.

 

P.s. I am not a nurse, just a flunky who works in an ER so I get to see extremes.

[regentrude]

It is actually possible, I have seen it a time or two, but it was extremely bizarre circumstances. Once was a aortic aneurysm repair and during surgery massive amounts of blood and fluid was required because of complications including acute renal failure.

 

I amended my previous post to include your experience.

[trulycrabby]

I have seen it too, although it's not common. Five to seven pounds is more common. I've never seen 20 pounds, but have heard it can happen. As Minnie stated, often trauma or other emergent situations which require blood and fluid IV combined with kidney shutdown ( which often seem to go hand) are how massive overnight fluid gains occur.

[trulycrabby]

Oops double post.

[Dmmetler]

I'm guessing in my case it was actually over more like a week, with the last several pounds being after being admitted to the hospital and put on IVs and blood transfusions due to HELLP syndrome. There were 10 days between my "before flying to see family for Christmas" OB appointment when everything was fine and being admitted to the hospital.

 

It was still a pretty scary experience.

 

 

 

[mhaddon]

Fluids just aren't taken in form of liquids, they are also excreated from anything that has been consumed. The body isn't properly filtering and flushing them out of the body. This can be contributed to many different reasons.

How big is the person that is gaining 20lbs?

[LucyStoner]

I experienced pre-e and the massive water weight gain in a short time. It's miserable. The edema is itself painful. It felt like my skin was going to pop. There's a lot of water in the food we eat and if urine production drops, water can add a lot and fast to your weight.

[Catherine]

All of the situations described involve retention of water that has been taken into the body via ingestion or IV fluids. Normally, kidneys will excrete all of that fluid. When they do not, edema or fluid in the abdomen or whatever can happen. But it has all been taken in *somewhere* and is not created new in the body. It's just leaked out of its proper containers. LOL.