PDF version: MIS 017 Diabetes [PDF 224 KB]
The word diabetes generally refers to diabetes mellitus and is usually used to describe a range of metabolic diseases that result in persistent elevated blood sugar levels. Diabetes usually occurs either because the body does not produce enough insulin or because the insulin that is produced does not have the normal effect. Since insulin is necessary for the body to absorb and use sugar in the blood, less insulin effect leads to higher levels of sugar in the blood. This, in turn, results in frequent urination (polyuria), increased thirst (polydipsia), and increased hunger (polyphagia). Over time diabetes can also lead to damage to many parts of the body.
Different forms of diabetes, and different severities, are treated in a variety of ways. Sometimes careful dietary management and weight loss is enough to manage a milder case whereas some more severe cases use insulin and other medications every day.
This page discusses diabetes mellitus, from an aviation safety viewpoint, and provides some guidance concerning how the CAA approaches the medical certification of applicants (pilots and air traffic controllers) with a history of diabetes.
Caution
This page contains general advice concerning the CAA’s regulatory handling of medical conditions. This sheet is not intended as clinical medical advice and should not ever be used as the basis of decisions concerning your medical care. You should consult your medical advisers and discuss your options thoroughly with them before making any decisions about your medical care.
While diabetes varies greatly in its severity and its cause, the features that can raise aviation safety concerns include the following:
High blood sugar levels can result in distraction and can interfere with your performance and decision-making.
Some treatments for diabetes can cause unexpected low blood sugar levels. Low blood sugar levels can interfere with performance, ranging from subtle impairment to complete loss of consciousness.
Diabetes leads to damage, over time, to a wide range of other parts of the body. This includes the heart, the eyes, the nerves, and the brain.
Yes. Blood sugar levels are required to be checked for class 1, 2, and 3 first-time applicants, and then periodically after that. A slightly different test, ‘HbA1C’, is a useful alternative to blood sugar tests, and is being used by some CAA Medical Examiners.
Some diabetics are eligible for unrestricted class 1, 2, or 3 medical certification. Others are eligible for class 2 but not class 1 or 3, and still others are declined any form of CAA medical certification.
Generally, diabetics who are adequately managed using diet-only are eligible for unrestricted medical certification. Diabetics who are adequately managed with medications that have a very low risk of causing low blood sugar (e.g. Metformin) may be eligible for unrestricted medical certification. Diabetics requiring other medication, not including insulin, may not be eligible for class 1 or 3 medical certification and may, depending on the details, be eligible for class 2 medical certification. Diabetics using insulin are not likely to be eligible for class 1 or 3 medical certification and some exceptional cases may be eligible for class 2 medical certification.
Insulin is a normal hormone that acts within our bodies. Some forms of diabetes are treated using injectable insulin to supplement the insulin produced by the body. Injected insulin acts to reduce the blood sugar levels and can sometimes lead to abnormally low blood sugar levels.
Class 2 applicants using insulin may be certificated if their diabetes control track record is excellent and if their risk of low blood sugar problems is very low. In such cases the CAA seeks long-term records to document the stability and safety of their diabetes management. Class 1 and 3 applicants using insulin are very rarely certificated. The exceptions are applicants who do not have ‘type 1’ diabetes, who do not use short acting insulins, and who do not use long-acting insulins close to the time of their next flight or ATC shift.
Yes. A diabetic can meet the medical standards if they are adequately controlled without the use of any drugs, or they are using (non-insulin) drugs with a very low risk of causing unexpected falls in the blood sugar levels.
If an applicant’s diabetes is not well controlled, requires insulin, or uses any drugs that have not been reliably shown to have a very low risk of causing unexpected low blood sugar levels, then they cannot be assessed as meeting the medical standards. That does not necessarily mean they will be declined a medical certificate but does mean that further consideration of their application will require the application of statutory flexibility and an Accredited Medical Conclusion (AMC).
Yes. If your diabetes is adequately controlled without medication you are able to meet the medical standards and, everything else being ok, you can expect to be issued an unrestricted medical certificate. You will probably be asked for notes and reports from your treating doctor as a part of the certification process.
The following information will be a good start to demonstrating reliable control over time without an unacceptably elevated risk of low blood sugar episodes.
Any medical certificate issued will carry a range of conditions and obligations, intended to ensure continued careful and safe management of the condition.
Possibly, but not necessarily. Some fastidiously controlled diabetic airline pilots who use only long-acting insulins in very specific circumstances have been issued restricted class 1 medical certificates.
Not necessarily. While there have been great advances in understanding, medication, and technology relating to diabetes the aviation safety risks of performance impairment and incapacitation risk remain a concern. Some of the modern technology equipment is very useful in the clinical management of diabetes but none of this equipment yet has a reliable enough track-record for aviation safety purposes. It is possible that that will change as time passes and more research is undertaken.
There are many new drugs available for the management of diabetes. Some of them have a tendency to cause unexpected low blood sugar levels, not a good thing, others appear relatively safe, and still others are so new there is not a very good published track record to consider.
It is not possible to make any general aviation regulatory statements concerning the newer diabetic drugs, and each case is assessed individually based on the details of that case.
Diabetes causes disease in small and large blood vessels. The blood vessels that lead to the heart can be affected by diabetes and this leads to diabetics having an increased risk of heart problems, including heart attacks. The method that the CAA uses to calculate cardiovascular risk allows for an applicant’s diabetic status.
What this means is that a diabetic, everything else being equal, is more likely to be required to undertake a stress test because of their elevated cardiovascular risk.
Diabetes can also damage the nerves. This can lead to many different problems but two that are particularly important to aviation are that a diabetic may not be able to reliably recognise the symptoms of low blood sugar levels, or of heart disease, if the relevant nerves are damaged.
You are always able to seek review of CAA medical certification decisions. For further information on review / appeal options you may wish to consult:
RIS 005 What Are My Review Options? [PDF 235 KB]
The civil aviation act contains no direct references to diabetes.
Rules 67.103(f) (Class 1), 67.105(f) (Class 2), and 67.107(f) (Class 3) include the medical standards relating to diabetes. The class 1 medical standards require that an applicant:
The class 2 and 3 medical standards are similarly worded.
There are no general directions that relate specifically to diabetes.
The ‘timetable’ general direction includes a requirement for how often tests for diabetes are undertaken as well as the requirements for cardiovascular risk assessment.
