I am suffering from mild haemophilia. Does any insurance policy cover pre-existing diseases?Pre-existing diseases are not covered by any insurer immediately at the commencement of the first policy because it means that there is a 100 per cent chance of the insured making a claim and is against the basic principle of insurance, which provides covers for uncertain eventualities. You can still take a medical cover, but it will exclude expenses incurred on the treatment of any pre-existing disease. Some insurers, however, cover diseases which exist at the time of taking the first policy provided the policy is continuously renewed for a specified number of years. This period varies from insurer to insurer and is generally between two and five years. Such policies are obviously slightly more expensive than normal medical covers.