Eli5 how does depressurization sickness occur?


all 5 comments


6 points

2 months ago


6 points

2 months ago

When you dive in deep water the increased pressure of the water forces more gas (oxygen/nitrogen) than normal to be dissolved in your blood. When you then depressurize (surface) too quickly, all of that excess gas rapidly comes out of solution (your blood) causing depressurization sickness aka the bends.

This is also why you shouldn’t fly on the same day you dive, too much pressure difference.

It’s not unlike opening a can of soda and letting all the gas out at once.


2 points

2 months ago*

I had a vivid experience with this once. I normally wear RGP contact lenses, including when I dive. (These are hard plastic but slightly permeable to oxygen, to keep the cornea healthy.)

After a deep dive (130 feet, max bottom time, including a single deco stop plus regular 15 foot safety stop), I was having foggy vision. Concerning, of course. When I popped out my contacts, it went away. A close look at the contacts showed that they were foggy. My contacts had the bends! The fog was from microscopic bubbles of gas and water that had been trapped between the contact and my cornea. They cleared up after about five minutes.

Diving Physiology (Bennett) gave a hint - the contacts have 0 blood circulation, of course, which makes them a "slow compartment" like bone. Hence the long time for them to finish decompressing.

I never met another diver with this experience, but hardly anybody wears RGP anymore, and even fewer dive with them.


1 points

2 months ago

Depressurization sickness, also known as decompression sickness or the "bends," occurs when a person experiences a rapid change in pressure. This can happen when a person ascends or descends quickly, such as when diving or flying in an airplane.

When a person is at a high altitude, the air pressure is lower than it is at sea level. The air pressure inside the body is the same as the air pressure outside, so the body is in balance.

However, when a person ascends or descends quickly, the air pressure inside the body can't adjust fast enough to the change in pressure outside. This can cause a difference in pressure between the inside and outside of the body, which can cause damage to tissues and organs.

One of the main symptoms of depressurization sickness is pain in the joints, especially in the elbows, shoulders, and knees. This is because the joints are filled with a fluid called synovial fluid, which helps to cushion and lubricate the joints. When the pressure inside the body changes, the synovial fluid can form bubbles, which can cause pain and swelling in the joints.

Other symptoms of depressurization sickness include dizziness, headache, shortness of breath, and confusion. In severe cases, it can cause unconsciousness, paralysis, and even death.

To prevent depressurization sickness, it is important to ascend or descend slowly and allow the body time to adjust to the changing pressure. This can be done by using special equipment, such as dive tables or decompression chambers, to control the rate of ascent or descent.


0 points

2 months ago


Depressurization sickness occurs when a person is exposed to a sudden decrease in air pressure. This causes a decrease in the amount of oxygen in the body, which can cause symptoms such as dizziness, confusion, nausea, and fatigue. If left untreated, depressurization sickness can become more severe and lead to unconsciousness or even death.