physiology Q3> diving, urination, and osmosis ?

[bradells]

The dive guides always ask us not to pee in the rental wetsuits. I understand the reasons for the recommendation but it always makes me laugh inside. I find this next to impossible. I suspect others to do. I usually have to pee 2 or 3 times per dive. I do try to rinse the wetsuit thoroughly before handing it back of course

I know the need to urinate occurs because of our body's attempts to maintain equilibrium. But I don't understand it other than that generalization. Is the sea water entering our body? or does our body need to use its own internal water to maintain some kind of electrolyte balance?

and the practical question> how important is it to drink fluids after diving to stay hydrated?

thanks.

I have no idea why, but near the end of dives (wetsuit or shorts), I gotta go. And especially once hitting the surface a few times more.

Definitely do keep hydrated (sips or gallons at a time), but stay away from things that may trigger your bladder (hot tea does it for me in the mornings).

I still have not peed in MY wetsuit, but rentals are a different story .....


BRad

 

[chillyinCanada]

I can tell when I'm not properly hydrated. No need to pee. Noticing thst generally gets me paying more attention to my fluid intake, in particular water. And I just feel better with more wster intake. That said, nothing seems to feel as good as letting go when you gotta go.

 

[gert7to3]

For warm water diving I bought a front zip 3mm wetsuit for white water rafting. It has a dual zipper so I pee outside my wetsuit.

In cold water with the 7mm, I hold it.

 

[Oldbear]

I once heard that there are three reasons why you urinate more frequently while diving. I have heard about immersion diuresis; what are the other two?

 

[Peter Guy]

I'm an instructor (but NOT a medical person) and, for kicks, I started talking about urinating and diving to pass the time for my students while they do the 10 minute float.

It is my understanding there are, in general, three issues involved:

a. Immersion diuresis -- as previously discussed;

b. Cold (particularly here in the PNW) which may cause the core blood volume to increase due to lower perfusion of extremities; and

c. Hydration -- if you drink a lot you are going to have to off load!

This talk generally keeps people from thinking about how boring the float is!

 

[agilis]

The mammalian diving reflex is a general term for some of the physiological changes in the human body that take place after immersion. Blood tends to partially leave the capillaries and extremities and becomes more concentrated in the body core. This affects the ways in which the kidneys respond. The diving reflex is essentially vestigial in humans, a reminder of our evolutionary ancestors.

 

[Salt]

Geez, i feel an urge to pee almost as soon as I jump in the water :blinking:

I assume the fluid distribution returns to normal after you dive when you are back on the boat. But by then the excess fluid has already been filtered in to your kidneys, no?

Is it better not to give in to the urge to pee then? The thinking being that urinating several times will actually remove water from the body and contribute to dehydration and if you dont pee the water stays in your body.

 

[agilis]

Geez, i feel an urge to pee almost as soon as I jump in the water :blinking:

I assume the fluid distribution returns to normal after you dive when you are back on the boat. But by then the excess fluid has already been filtered in to your kidneys, no?

Is it better not to give in to the urge to pee then? The thinking being that urinating several times will actually remove water from the body and contribute to dehydration and if you dont pee the water stays in your body.

I'm certainly not an authority, but it seems to me that once the kidneys have done their work, retaining urine in the bladder will not counter dehydration. The trick is to start well hydrated and avoid things like alcohol and diving while fatigued. And it goes without saying that if you really are concerned about decompression sickness you will never push the tables or operate on the edge of your computer's safety margin. As Forrest Gump observed, 'stupid is as stupid does'.