Dizziness and Impaired Vision Are Key Signs of Air Embolism for Scuba Teams.

Which of the following is a symptom of air embolism?

• A. Swelling of the limbs
• B. Muscle spasms
• C. Dizziness and impaired vision
• D. Skin rash

Answer: (C)

Dizziness and impaired vision are indeed classic symptoms of air embolism. An air embolism occurs when air bubbles enter the bloodstream, which can happen during diving if a diver ascends too quickly after spending time at depths where pressure is significantly higher. The presence of air bubbles can disrupt normal blood flow and cause various neurological symptoms due to a lack of proper blood supply to the brain. Dizziness may manifest as feelings of lightheadedness or a sense of vertigo, which can significantly affect a diver’s ability to maintain control while underwater. Impaired vision, which may include blurred or tunnel vision, occurs due to the bloodstream not effectively delivering oxygen to the optic nerves or brain regions responsible for vision because of the obstruction caused by the bubbles. Recognizing these symptoms is critical for divers, as they indicate the need for immediate medical attention to prevent serious complications, including stroke or death.

Air embolism is one of those terms that sound like medical jargon, but it’s a real safety concern that can pop up in open-water training if things aren’t done carefully. Let me explain what it is, why it matters, and—the part you’ll care about most—the clear symptom to watch for so you can act fast if something seems off.

What exactly is an air embolism?

Think of your bloodstream as a busy highway. If air bubbles slip into the system, they act like traffic jams. Those bubbles can block blood flow to critical organs, especially the brain and heart. In the context of underwater training, the main risk comes from rapid ascent or other pressure-related issues that allow air to form bubbles that travel through the vessels.

To keep it simple: air embolism is when air bubbles end up where they don’t belong in your circulatory system. That sounds alarming—and it is. It’s not something to shrug off, because bubbles can disrupt oxygen delivery where it’s most needed.

Why does it happen during ascent?

Pressure changes are part of every underwater adventure. Water pressure at depth compresses air inside your lungs and tissues. If you ascend too quickly, that compressed air can expand and form bubbles in the blood. You can also get bubbles if you hold your breath during ascent, which creates pressure changes in the chest and lungs. Both scenarios can lead to bubbles entering the bloodstream and traveling to the brain or spinal cord, causing symptoms that can escalate quickly.

This is why open-water training emphasizes controlled ascents, smooth buoyancy, and careful breathing. It’s not just a ritual; it’s a safety protocol that saves you from preventable trouble.

The telltale symptom to notice: dizziness and impaired vision

There are a few signals you might notice if air bubbles start causing trouble. But the one you want to recognize early is dizziness paired with impaired vision. In plain language: you feel off-balance, lightheaded, or as if the world around you is tilting. Your vision might blur, narrow (tunnel vision), or feel hazy. It’s not just a momentary wobble; it’s a warning sign from your body that something isn’t circulating properly.

You might also hear folks talk about other possible symptoms, like headaches, confusion, difficulty speaking, numbness, weakness on one side, or a feeling of “pressure” in the chest. Those aren’t the only signs, but they’re important. Still, dizziness plus impaired vision are the classic red flags—clear, noticeable, and hard to ignore.

Why those symptoms become a big deal

Your brain depends on a steady supply of oxygen-rich blood. When bubbles disrupt that supply, brain cells can’t function as they should. The consequences range from a foggy sense of balance to more serious conditions, like stroke, if treatment is delayed. In the worst cases, untreated air embolism can be fatal. That’s why recognizing the warning signs and acting quickly matters so much.

What to do the moment symptoms appear

If you or your buddy notices dizziness and blurred or impaired vision, treat it as an emergency. Here’s a practical, no-nonsense sequence:

• Stop the ascent and hover calmly at a safe depth or at the surface, depending on the situation.

• Tell your buddy or the surface team right away. Use clear, direct language: “I feel dizzy and my vision is blurry. I think I have a problem.”

• If you’re trained and there’s oxygen available, administer 100% oxygen while arranging for urgent medical help. Oxygen helps reduce bubble size and improves oxygen delivery to the brain.

• Surface safely and seek medical care immediately. Hyperbaric treatment is the standard, definitive therapy for air embolism and decompression-related injuries. Don’t wait to “see if it goes away”—timing matters.

• If you’re with a group, designate someone to call emergency services and one to guide responders to your exact location.

Think of it like any other medical alert: you don’t wait for symptoms to worsen before acting. Quick, calm, decisive steps can make the difference between a temporary scare and a life-changing outcome.

Prevention: how to lower the chances of trouble

The best way to handle air embolism is to keep it from happening in the first place. Here are practical, field-tested tips that wearable gear makes easier than you’d think:

• Ascend slowly. The rule of thumb is simple: never rush a ascent. A slow rise gives the body time to offload excess nitrogen safely.

• Practice safety stops. A short stop at about 5 meters (15 feet) helps your body adjust as you move toward the surface.

• Never hold your breath. Breathe steadily throughout the ascent. It’s a rhythm you and your buddy should practice until it’s second nature.

• Maintain good buoyancy control. Smoother buoyancy means less stress on ascent and less risk of rapid, uncontrolled movement.

• Stay with your buddy. The buddy system isn’t just for photos; it’s a safety net. If something goes wrong, the partner on your side can initiate help quickly.

• Check equipment and environment. A simple pre-entry check—mask, regulator, buoyancy device, and surface conditions—goes a long way. Small issues can compound during ascent.

• Know your limits. Don’t push too far or too deep for your current training level. Incremental progress keeps risk far lower.

• Get proper training. Instructors who emphasize safety stops, breathing discipline, and careful ascent plans are teaching you a lasting habit that pays off when things feel off.

A few real-world tangents that help the point land

• As you hike through your training, you’ll hear about the “safety stop” as a recurring theme. Some folks treat it like a boring ritual; others see it as a crucial, life-saving pause. The truth is somewhere in the middle: it’s a tiny moment that buys time for your body to equalize and shed excess nitrogen before the next move.

• You’ll notice that oxygen becomes a recurring hero in the narrative. It’s not a magical cure-all, but it’s a simple, powerful tool when used promptly. In many systems, emergency oxygen is standard-issue on boats and in medical settings. Knowing how to access and apply it can be a lifesaver.

• The psychology of safety matters, too. When you’re new to the water, the fear of being “wrong” is real. The best antidote is practice that’s deliberate, guided by an instructor, and anchored in a calm, reflective mindset. If you feel uncertain, surface with your buddy, talk through the plan, and reset before resuming.

What this means for your open-water journey

You’re training to become more capable, not to impress anyone with bold moves. The hallmark of a skilled diver is not the thrill of a rapid ascent but the discipline to manage pressure, breathe steadily, and act decisively at the first sign of trouble. Dizziness with impaired vision is a strong signal that something isn’t right. Treat it with gravity, respect the chain of actions, and you’ll protect yourself and your companions.

A short story to illustrate the point

A buddy pair finds themselves at a pleasant depth, enjoying the moment, when one person suddenly feels lightheaded and sees the world blur at the edges. They pause, share the concern, and switch to a slow, controlled ascent while their partner remains calm, follows the plan, and communicates clearly. They surface with time to spare and seek medical care promptly. The outcome isn’t dramatic because the reaction was measured and timely. It’s a quiet reminder that safety isn’t about bravery; it’s about preparation and teamwork.

Key takeaways, wrapped in a simple package

• The classic symptom to watch for is dizziness paired with impaired vision. It’s your early warning signal.

• Air embolism happens when air bubbles enter the bloodstream, often due to rapid ascent or breath-holding—conditions you can influence with good technique.

• If symptoms appear, stop ascent, stay calm, provide oxygen if you’re trained, and seek emergency care right away. Hyperbaric treatment is the definitive step.

• Prevention matters as much as response: ascend slowly, perform safety stops, breathe normally, maintain buoyancy, and dive within your training level with a trustworthy buddy system.

• Training should reinforce these habits, turning them into second nature so you react automatically when something feels off.

A final nudge toward practical reliability

If you haven’t yet, have a candid chat with your instructor about how to recognize and respond to symptoms like dizziness and impaired vision. Practice the ascent plan in controlled environments until it becomes muscle memory. Invest in a buddy system you both trust and refine your emergency response so you can act without hesitation. After all, the underwater world rewards calm, preparation, and teamwork as much as it rewards curiosity and skill.

As you continue through your open-water training, keep your eyes open for those little signals your body gives you. They’re not scareware; they’re safety signals. When you listen and respond, you keep underwater adventures enjoyable, educational, and—most importantly—safe for you and everyone around you.