Appreciate can be a good alternative to ‘understand’.
When speaking to patients, if you have no direct experience of what they are facing, it is not very appropriate to say ‘I understand you’. Instead you can use ‘appreciate’ to suggest you can imagine what it must be like even if you don’t know exactly.
Swapping ‘appreciate’ for ‘understand’, can mean a lot to the patient. These little changes can make them feel you are really listening to their concerns and trying to help them.