DIABETES IS A DISEASE that affects the endocrine system, the collection of glands that produce hormones regulating your metabolism, growth and development, tissue function, sexual function, reproduction, sleep and mood, among other things. And for many years the medical community advised against diving with diabetes.
The main threat is the effect that diabetes has on your pancreas, the organ that produces insulin and glucagon.
These are the two hormones that balance and maintain our blood sugar, or blood glucose (BG).
As of 2015, an estimated 415 million people were suffering from diabetes worldwide, and by 2040 the have risen to around 642m. In the UK alone, an estimated 4.5m people live with diabetes.
Does this mean that diabetics are not allowed to dive? Absolutely not! 

Having diabetes means either that your pancreas is not producing enough insulin, or that the cells of the body are not responding properly to the insulin produced. There are two main types of diabetes:

Type 1 entails the pancreas failing to produce enough insulin, which leads to insulin-dependency and the need for insulin injections. The cause of Type 1 diabetes is currently unknown.
Type 2 begins with insulin resistance, a condition in which cells fail to respond to insulin properly, which may also lead to a lack of insulin. This type of diabetes can be controlled by maintaining a healthy diet and by taking oral medication. The most common cause of Type 2, by far the most common form of diabetes, is an unhealthy lifestyle, excessive body weight and lack of exercise.

Medical experts have advised against diving with diabetes because of the fragile and potentially life-threatening conditions diabetics may encounter when suffering from high BG (hyperglycaemia) or dangerously low BG (hypoglycaemia).
Insulin (and physical exercise) lowers your blood sugar, while glucagon (as well as foods with glucose) raises it.
Diabetics may often suffer from overly high and low sugars, which puts them at a much higher risk of suffering from an accident under water. This means that diving in a state of hyperglycaemia or hypoglycaemia may lead to loss of consciousness and in some cases even death. This is why medical experts have raised a red flag about diabetics diving, especially when the would-be diver’s illness is unstable or newly discovered.

Common risks, symptoms and effects of diabetes include:

Hyperglycemia (high BG): Extreme thirst, frequent urination,
dry skin, hunger, blurred vision, nausea, drowsiness, slow-healing wounds, vomiting.
Hypoglycemia (low BG): Trembling, fast heartbeat, sweating, dizziness, anxiousness, paleness, hunger, weakness/fatigue, headache, fainting.

When in doubt, diabetics must immediately check their blood sugar using a BG monitoring device, and either eat or drink something with sugar when their BG is low, or else take the appropriate medicine to counteract high blood glucose.
Symptoms and precautions are difficult, if not impossible, to identify and manage under water, and because of the scope of these potential problems, diabetics are at greater risk when it comes to diving safely.
Some medical experts disapprove of diabetics diving even today, yet in recent years many divers with the condition have proved the medical industry wrong, and shown that it is possible to pursue their passion for diving without jeopardising or sacrificing health and safety.
It’s a matter of taking the right precautions, and knowing your limits. Always speak to professionals to get an objective opinion of the state of your health before attempting to dive.
No matter how well-controlled your condition may be, if you have diabetes you can’t dive without restrictions.
The same applies to people without diabetes, of course, yet diabetics must accept that, however good their diving skills, their risks are higher.

Results from research by DAN Europe suggest that to prevent worsening of hypoglycaemia and to correctly interpret hypoglycaemia-like symptoms while diving, diabetic divers can benefit from real-time BG monitoring on their dives.
In a study, 26 dives were recorded with no statistical difference between the BG recorded every five minutes before, during and after dives.
Another study by the DAN Europe Research Division came up with similar results, suggesting that diving does not imply significant risk of hypoglycaemia even if continuous monitoring showed a progressive lowering of BG levels.
The general conclusion of such studies is that diabetic divers should take a real-time Continuous Glucose Monitoring (CGM) unit in a waterproof case on dives, giving them immediate information on blood-glucose values and trends.
This offers a significant increase in diving safety, and should provide further encouragement for diabetics to try diving.

Provided you don’t suffer from any long-term complications, undergo regular check-ups and keep your diabetes well- controlled to avoid any potential threats, diving with the condition is totally acceptable.
Our mission is that everyone should succeed in diving safely, so that we can
all share our passion for exploring the world’s enchanting waters.
If you’re thinking about diving with diabetes, or know someone who is, take a moment to go through the recommendations in the panel above.
And if you do dive with diabetes, please share your thoughts, tips and experiences with us on Facebook
@DAN Europe.

14 recommendations for divers with diabetes

  • Speak to a doctor and diabetes/diving specialist before attempting to dive.
  • Always wear a diabetes bracelet so that fellow-divers are aware in case of an emergency.
  • Carry oral glucose with you at all times and make sure your buddy is aware and has some too.
  • Have a glucagon injection on-site (at the surface) in case you lose consciousness.
  • Eat food with slow-digesting carbohydrates before diving to ensure a balanced glucose level.
  • Measure your blood glucose immediately before and after diving.
  • Avoid depths greater than 30m – nitrogen narcosis can be confused with hypoglycaemia!
  • Avoid diving for longer than 60 minutes.
  • Log your dives and take note of your blood sugars for future reference.
  • Do not dive in cold waters, strong currents or conditions that demand strenuous activity.
  • Ensure that you have a stable blood sugar no less than 150 mg/dL (8.3 mmol/L) with Type 1.
  • Consider using a Continuous Glucose Monitoring (CGM) system to check your BG in real-time.
  • Stay hydrated and healthy before, during and after diving.
  • Remain relaxed and enjoy the experience.

I’ve occasionally had problems clearing my ears, particularly my right ear, and I take medication for allergies and nasal congestion. A couple of months ago I got a sinus infection, and in the weeks that followed I saw my regular doctor once and an ear, nose and throat (ENT) specialist twice for congestion and muffled hearing.
The doctors noted fluid behind both eardrums on each visit, and prescribed three separate courses of oral steroids and antibiotics. I’m going back to the ENT in a few days, and I think I may still have fluid in my right ear (I can feel air moving when I yawn).
The specialist said that he would want to insert tubes if the condition hasn’t resolved.
I am concerned about the amount of time this procedure would keep me out of the water, and about the potential for scarring of my eardrums. Do you know of any other options besides ear tubes for draining the fluid?

Unfortunately, it sounds as if your doctors have exhausted all options for resolving the congestion in your ear. The purpose of steroids is to reduce inflammation and allow the fluid to drain via the Eustachian tubes. Fluid that stays in the ear for extended periods can promote bacterial growth, leading to a risk of middle-ear infection.
Antibiotics serve as a means to fight or prevent such an infection. If oral steroids, decongestants and antibiotics have not solved the problem, then ear grommets are the next logical step.
You are correct that grommets pose a risk of scarring on the tympanic membrane or eardrum, but they are unlikely to affect your ability to dive in the future. Grommet insertion is a fairly benign procedure.
Following your doctor’s advice would be prudent – if he believes that grommets are the best way to resolve this problem, it makes sense to proceed.
Although diving with the grommets in place is strongly discouraged (because of the high risk of middle-ear infection and vertigo from incursion of water), after they’re removed or fall out on their own and after a healing period of at least six weeks, diving is generally possible.
Before you dive again, go back to your doctor to ensure that your eardrums have healed fully and function properly. Should your doctor have any dive-related questions, please encourage him to contact DAN.

DAN Europe is a not-for-profit worldwide organisation that provides emergency medical advice and assistance for underwater diving injuries. It also promotes diving safety through research, education, products and services