Scuba Diving and Diabetes

For many years the medical community discouraged people with diabetes from scuba diving. A Divers Alert Network® (DAN®) survey in 1996, however, revealed that nearly 200 of its members were divers with some form of diabetes. After an observational research study in 1997 and a workshop attended by more than 50 clinicians and researchers in 2005, DAN and the Undersea and Hyperbaric Medical Society (UHMS) changed the guidelines for divers with diabetes. Today, diabetics who use medication — oral hypoglycemic agents (OHAs) or insulin — or diet to treat their diabetes may participate in recreational scuba diving, provided certain criteria are met.

Diabetes mellitus is an endocrine system disorder in which either the pancreas does not produce enough insulin or the body’s cells do not respond properly to the insulin produced. In Type 1 diabetes, the pancreas cannot produce enough insulin, requiring insulin injections to control blood glucose (sugar) levels in the body. With Type 2 diabetes, the body’s cells fail to properly respond to insulin (insulin resistance); dietary changes and oral medication can help manage this type of diabetes.

Is It Safe for People with Diabetes to Scuba Dive?

Many people with controlled diabetes can enjoy scuba diving. Diabetic divers who manage their condition with diet and/or medication but who are otherwise healthy enough to dive may participate in recreational scuba activities with a physician’s approval. Follow the guidelines listed later in this article along with any physician recommendations, and consider these additional facts:

• The risk for hypoglycemia is higher for Type 1 diabetics, but the condition can also occur in those who have Type 2 diabetes or anyone taking OHAs.
• Diabetics with a newly diagnosed or unstable condition face the greatest risk of a medical problem.
• Divers with diabetes should be examined periodically for complications of their disorder that may disqualify them on the grounds of additional risk.

What Are the Risks for Divers with Diabetes?

Doctors often discourage diabetics from scuba diving because of the potentially life-threatening conditions the condition can cause: hyperglycemia and hypoglycemia. The symptoms and effects of hypoglycemia (low blood sugar) include fatigue, shakiness, confusion, rapid heartbeat, sweating, loss of consciousness and even death. At depth, hypoglycemia may be misperceived as nitrogen narcosis.

Hyperglycemia (high blood sugar) may also cause unconsciousness; however, this condition develops more slowly than hypoglycemia. Among the symptoms of hyperglycemia are blurred vision, drowsiness, dry skin, increased thirst, frequent urination, hunger, slow-healing wounds, nausea and vomiting. Some Type 2 diabetics may not show any noticeable symptoms.These symptoms are difficult to identify and manage underwater, and unconsciousness underwater can lead to drowning and significant risk for the diabetic diver’s dive buddies.

Guidelines for Divers with Diabetes

• Before trying scuba diving, discuss your condition with a physician who specialises in diabetes and/or dive medicine.
• If you’re cleared to dive, tell your dive buddy and the dive operation staff about your condition.
• Wear a diabetes medical alert bracelet in case of an emergency.
• Carry oral glucose at all times, and tell your dive buddy and the dive operation staff where to find it and how to administer it in an emergency.
• Have a glucagon injection available at the surface.
• Eat food with carbohydrates that are slow to digest before diving to encourage a balanced glucose level.
• Measure your blood glucose several times before diving (including immediately before) and do so again afterward. Insulin requirements may change substantially with the demands of exercise and diving.
• Do not dive deeper than 100 feet (30 meters). Hypoglycemia can be confused with nitrogen narcosis, which has an increased likelihood of developing at depths greater than 100 feet.
• Avoid diving for longer than 60 minutes.
• Log your dives, and note your blood sugar levels for future reference.
• Do not dive in cold water, strong currents or conditions that demand strenuous activity.
• Consider using a continuous glucose monitoring (CGM) system for a real-time check of your blood glucose levels.
• Stay hydrated and healthy before, during and after diving.

Get Screened

The Centers for Disease Control and Prevention (CDC) estimates 9.4 percent of Americans have diabetes and almost 24 percent of those people are undiagnosed. The American Diabetes Association recommends that individuals without symptoms or risk factors get screened for diabetes every three years beginning at age 45. Individuals who are overweight or obese or who have other risk factors (such as high blood pressure or a family history of diabetes or heart disease) should begin diabetic screening earlier.

People diagnosed with prediabetes do not always develop Type 2 diabetes. Healthy lifestyle choices — including 30 minutes of exercise five times per week, weight loss and a healthy diet — can prevent or delay Type 2 diabetes. On the flipside, people with undiagnosed diabetes have an increased chance of heart disease, stroke and other serious conditions.

Additional Reading

• Guidelines for Diabetes and Recreational Diving Guide
• Diabetes and diving infographic