Scuba Diving Depth and Blood Pressure

by Gary Lazarus
(Bellingham, WA)

Is there any correlation between one's blood pressure and the depth to which they descend? In other words, does one's blood pressure increase at depth?

Hi Gary,

That is an interesting question and one I had never thought about (I will note, though, that I do not have high blood pressure).

It was hard to find an adequate answer to your question but I finally found it in the March/April 2009 issue of Alert Diver magazine.

In case you aren't familiar with it, Alert Diver is the magazine put out by DAN (Divers Alert Network).

DAN, for those that don't know them, is a highly regarded non-profit "medical and research organization dedicated to the safety and health of recreational scuba divers and associated with Duke University Medical Center." I have been a member of DAN since I started diving. Their website is www.diversalertnetwork.org.

They have an excellent article about scuba diving and hypertension in their latest issue.

This is what they had to say about high blood pressure and diving:

"If controlled properly, moderately HBP (high blood pressure) does not compromise fitness to dive. If your blood pressure remains high despite treatment, or if it is erratic, you should avoid diving."

And they go on to answer to your question:

"Diving increases blood pressure, even in divers with normal pressure. This occurs due to the immersion-caused shift of the blood into the thorax, the constriction of peripheral blood vessels and exercise. Divers with high blood pressure that is not well controlled face a significant risk from immersion and cold: Together they can cause a sudden increase in blood pressure that can cause liquid from the capillaries to leak into the alveoli and flood the lungs. This is an acute life-threatening condition called immersion pulmonary edema."

So the answer to your question, thanks to DAN, is that yes, your blood pressure increases when you scuba dive.

Sorry it took me awhile to get back to you. Hopefully this answers your question.

I wish you all the best and safe diving.

Dianne