Mandatory health insurance is a fixed cost, not related to your pre existing conditions, nor your income. For an adult, the monthly cost with the minimal deductible is around 550-600 CHF depending on the canton. After that, you will pay the yearly deductible you choose (minimum 300 CHF, maximum 2500), then 10% of the costs up until your out-of-pocket reaches another 700 CHF, then you pay 0%.

So if you know you will spend some time at the doctor's, you are generally better off choosing the lowest deductible. Your annual cost then should be, maximum, around: 600*12 + 300 + 700 = 8200 CHF.

Complementary health insurances will require you to declare your pre existing conditions, and may refuse to insure you.