If you're advised against travelling by your doctor, the good news is that your travel insurance policy can provide cover for the cost of cancelling your holiday. This includes cover for any cancellation fees you're required to pay, as well as any pre-paid deposits for accommodation, tours and the like that are non-refundable.
You can also take advantage of trip interruption cover from your travel insurer. For example, if an unexpected complication develops during your journey and treating doctors recommend that the best course of action is for you to return home and rest, travel insurance can cover the cost of your forfeited pre-paid expenses and also the additional flights needed to get you home safely.