Why Do I Get a Nosebleed After Diving?
Candace Reno February 11th, 2025 Posted In: Articles Tags: SCUBA
Have you ever surfaced from a SCUBA dive and suddenly your nose started bleeding? It can be really scary to surface, remove your mask, and see blood come flowing out of your nose! Don’t be alarmed though! Although it’s not a pleasant feeling, in itself, the nose bleeding is not necessarily a sign of a serious problem.
What Causes Nosebleeds After SCUBA Diving?
Not being able to equalize your air spaces properly either on descent or ascent can result in nosebleeds after SCUBA diving. Why? Pressure!
Pressure
Let’s first recall the physics of SCUBA diving. As you descend, there is an increase in pressure. Every 33 feet, pressure increases by one atmosphere. This is not a problem for our bodies as we are mostly made of water and pressure has no effect on water.
However, pressure does have an effect on air spaces. As you descend, air spaces will compress. On the contrary, as you ascend, air spaces will expand. What are the air spaces while SCUBA diving?
Air Spaces of the Body
Air spaces of the body, particularly the ears, play a crucial role in SCUBA diving safety. Proper equalization techniques, such as gently pinching your nose and blowing or wiggling your jaw, help manage pressure changes during descent. Forceful attempts should be avoided to prevent potential damage, including post-dive nosebleeds.
Ears
The air space inside the ears can be equalized while descending by pinching your nose and blowing gently or wiggling your jaw side to side. Avoid forceful equalizing attempts as this could cause damage and actually be a source of nosebleeds after SCUBA diving. While descending, if you are unable to clear your ears, you should ascend to shallower depths and try again.
Sinuses
The sinuses are usually cleared when you equalize your ears. If you have allergies or have been sick recently, you might have sinus pressure that cannot be equalized with anything but time to heal and recover.
Lungs
The lungs are the biggest air space of concern to divers. The number one rule of SCUBA diving is to never hold your breath. A breath hold followed by ascent could lead to lung overexpansion injury which can be very serious, even fatal. You keep your lungs safe by continually breathing.
Mask
Your mask has an air space which allows you to see clearly underwater. If the mask squeezes, you blow gently out of your nose to relieve the pressure. Not doing so can lead to blood vessels on the eyes becoming inflamed or broken.
Barotrauma
Now that we know more about the physics of diving, let’s get back to what causes a nosebleed after SCUBA diving. A bleeding nose after SCUBA diving is technically called a sinus barotrauma. This occurs due to pressure on the paranasal sinuses from vertical movement which does not equalize. This should result in facial pain while it is happening. The blood vessels lining the membranes will burst leading to drainage and a potential bloody nose. Most divers do not know their nose is bleeding until they surface.
Pressure not equalized on descent will create a sort of vacuum and cause barotrauma. Once the equalization occurs underwater, there is relief, but the pressure from the descent forces the build up of blood out of the nose.
Pressure on the ascent is known as a reverse block and is rarer. This usually occurs because of a cold or medications used for a cold have worn off. Normally, you do not need to do anything to equalize on the way up. This happens naturally. But with reverse block, the pressure can again build and cause the sinus walls to burst and lead to a nosebleed upon surfacing.
How Do You Tell Your Buddy You Are Having Trouble?
If you are having trouble clearing your ears, you should signal to your buddy the “something’s wrong” hand signal and point to your ears. If you feel pain in your face, you should point to your face. Signal up during both these cases to let your buddy know it’s time to go shallower or maybe even have to abort the dive.
History of Nose Problems
If you have a history of a broken nose or deviated septum, you are more at risk for nosebleeds after SCUBA diving. You should be checked out by a doctor prior to diving to make sure it is safe for you to do so.
How to Prevent a Nosebleed After Diving
The simplest way to avoid nosebleeds after diving is to not dive while sick. Congestion can make it very difficult to clear your ears and sinuses. This is the most common reason someone has a nosebleed after diving. Using proper equalization techniques is also important to prevent nosebleeds.
I have seen many divers with a nosebleed after SCUBA diving. I usually recommend they see a doctor to make sure nothing else is going on and it is safe for them to continue diving. If you find yourself most commonly having a nosebleed after surfacing from a dive, you might have something else going on that needs to be checked out. Stay safe and make sure you equalize your ears and sinuses with ease on a dive. Do not force it or you could be the one with a bloody nose after SCUBA diving!
