Since 1997
Bladder Discomfort
by DAN Medical Team on March 1st, 2016

​As an inexperienced diver, with less than 50 dives since being certified last year, I have an unrelenting dilemma. No matter how many times I void, I always end a dive having to desperately go to the bathroom. My stomach will be bloated and I can't get my tank and wetsuit off quickly enough. I purposely don't drink before a dive, except two cups of morning coffee, and it seems I should be properly hydrated.

I go to the bathroom before I get in the water and immediately after the dive. (I refuse to urinate in my wetsuit.) How can I control this? I don't have a weak bladder or any form of incontinence. 
​The answer to this interesting dilemma is based on an understanding of dive physiology. The phenomenon you describe is known as immersion diuresis and occurs whenever the body is emerged in water. Immersion, along with a water temperature that is colder than air, causes narrowing of the blood vessels in the extremities. This vasoconstriction occurs primarily in the skin and superficial tissues of the body as well as in the muscles of the arms and legs. The result: An increased volume of blood is sent to the central organs of the body such as the heart, lungs and large internal blood vessels.

The hormone that controls the production of urine by the kidneys is called antidiuretic hormone (ADH). It controls when and how much urine your kidneys make. The increased blood volume to the major vessels is interpreted by your body as a fluid overload. This overload causes ADH production to stop, which in turn allows the kidneys to immediately produce urine to lower the centrally circulating blood volume the body's automatic response to preserve blood volume. Once you exit the water, circulating blood volume returns to near normal-less the fluid taken to produce urine, which is quickly replaced as the body draws fluid from body tissues, such as muscles.

Unfortunately, you probably will also leave the water with a full bladder. Since we are all subject to the same phenomenon underwater, this is probably your normal response to immersion. If this situation causes problems like urinary tract infections, see your doctor.

If your coffee is caffeinated, you may wish to switch to a decaffeinated brand, as caffeine is a known diuretic that also interferes with the production of ADH.


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6 Comments

Rosemarie Solomon - April 21st, 2016 at 2:44 AM
This is interesting, as I have always suffered the same problem, as a diver. It's great to know it's normal and I now know who the wet suit "pee-ers" are. they are the ones not charging for the toilets after a dive.
Raven - April 21st, 2016 at 3:03 AM
Stop the refusal. Science says: pee in your wetsuit. Hence the wetsuit shampoo market. ;)
Many people get urinary tract infection simply because they refuse to listen to mother nature.
It is always useful to note the many effects entering water, (nevermind compression during diving) have on the body, i.e. lowering of heart rate, pupil dilation, hormonal releases etc


Lorenzo Pelli - April 21st, 2016 at 4:20 AM
Well then... 50 dives and he refuses to wee in his wetsuit.... we go back to the 3 categories about this: the ones who do (I've doing it for ever, and infact it also happens during swimming sessions, so unlike many people believe, this natural reaction of the body is not related to depth or pressure), then the ones who lie.... and our friend here is one of the "ones who will".... Why make a fuss and suffer from a perfectly normal and natural situation...
Carol - April 21st, 2016 at 4:25 AM
I drink lots of water and pee in my wet suit. In fact it's like I have to go. Plus it gives you a nice warm feeling when the water is cold.%uD83D%uDE1C
R mccrory - April 21st, 2016 at 6:41 AM
Not in a dry suit. Interesting
DAN Medical Team - April 22nd, 2016 at 12:35 AM
Thanks for this string of comments and contributions!

Pool hygiene issues aside - it is definitely better to urinate in the wetsuit than hold it in! Apart from the discomfort, irritation of the bladder and prostate, and increased chance of urinary infection, there is another danger: People often deliberately deny themselves fluids and dehydrate themselves to avoid urinating in their wetsuits. This is very, very unwise, as it increases the risk of decompression illness significantly. In fact, DAN is actively busy with a "More water less Bubbles" campaign to try to offset this tendency! We offer our apologies to pools and wetsuits in advance!

Check it out on: http://www.dansa.org/more-water-less-bubbles.htm.

Safe Diving!

DAN Medical Team
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