Medical Issues in Scuba Diving

Diving places unique demands on the human body. While most recreational dives go smoothly, it's important to understand the medical risks that can arise underwater, how to prevent them, and what to do if something goes wrong. This section brings together key conditions, practical advice, and the underlying science, all grounded in training-level relevance without unnecessary complexity.

Being informed is not about fear, it is about responsibility. The more you know about diving-related medical issues, the better your decisions, your dive planning, and your ability to help others.

Decompression Illness (DCI): DCS, AGE, and the Role of PFO

Decompression illness (DCI) includes both decompression sickness (DCS) and arterial gas embolism (AGE), and it can affect even conservative recreational divers. This page explains how both conditions occur, what symptoms to look for, and how to respond. It also covers how a patent foramen ovale (PFO) may increase your risk of neurological DCS, even when you follow all the rules. Learn how to protect yourself, recognize an undeserved hit, and be prepared with oxygen, training, and the right team.

Central Nervous System (CNS) Oxygen Toxicity

CNS oxygen toxicity is a rare but deadly condition that can strike without warning when diving nitrox or using high-oxygen mixes. This guide explains how it happens, what symptoms to watch for, and why proper gas planning and staying within PO2 limits is critical. It also gives direct, actionable steps for what to do if a seizure occurs underwater—and firmly addresses the risks rebreathers introduce for recreational divers.

Understanding Nitrogen Narcosis

Nitrogen narcosis is a common but misunderstood effect of diving deep on air. This guide explains why it happens, how to recognize it, and what to do when it occurs. Plus how your dive team plays a critical role in managing its risks.

Motion Sickness Tips

Motion sickness can ruin a dive day before you even hit the water. This guide covers why it happens, what medications and techniques actually work, and how to handle it if it hits you onboard or underwater. Whether you're prone to nausea or just want to be prepared, these strategies will help you enjoy your dive day without distraction.

Avoiding Leg Cramps

Cramps can hit hard during a dive...especially in your legs during long swims or finning against current. This guide covers the most common causes of dive-related leg cramps, along with practical strategies to prevent and manage them. Whether you're dealing with tight muscles, hydration issues, or poor fin technique, you'll find realistic, experience-based tips that can help reduce cramping before, during, and after the dive.