Health insurance companies are protecting a risk and, like any insurance company, they try to keep the risks they insure as low as possible. So, the better your medical history is, the less likely they are to have to pay out a claim on your policy and the lower your premium will be.

Your medical history may also determine what type of private medical insurance you will be eligible to get. If you have diabetes, asthma or another chronic, incurable condition, for instance, most private insurers will exclude coverage for anything related to treatment. Some, taking into account the number of other conditions and illnesses for which those are a risk factor, will refuse to insure you at all. In general, that means that if you know you are ill, or that you will require medical treatment in the next six months because of a medical diagnosis, you may have trouble finding private health insurance to cover your needs.

There are many private health insurers who do not require a medical history, or only require a very basic one. In general, their policies will exclude coverage for any condition for which you have been treated in the past five years, or another specified period of time. If you remain free of symptoms and require no treatment for that condition for the specified period of time after you become insured, that condition may become eligible for cover again.

If your prospective insurer does ask for a medical history, you should always be truthful and declare everything you are aware of at the time. Any errors, omissions or outright lies in your application could negate your policy entirely. It is better to have coverage for unrelated illnesses and conditions than to have no coverage at all.

So, should you bother with private medical insurance if you have a pre-existing chronic condition? Most experts would say yes. The NHS is designed to provide care and treatment for chronic conditions like asthma and diabetes. Your private medical insurance would still provide cover for you for illnesses, injuries and conditions that do not arise from your pre-existing chronic condition. In addition, if you have been treated for an illness in the past five years ulcers, for instance and have remained symptom free for five years, most policies will cover treatment for that condition if it recurs.

Interestingly, a number of UK private medical insurance providers do offer chronic conditions cover for UK expatriates. Most continental insurers do not exclude chronic conditions in their policies, and UK companies doing business overseas are beginning to follow suit. If you are seeking medical insurance for a period of time abroad, shop around to find one that will cover all of your needs during your time away.