There are two main types of diseases communicable diseases and incommunicable diseases. Communicable diseases are caused by a virus and bacteria. Example of communicable disease is HIV, COVID-19, Smallpox, Chickenpox, Flu, and so on.
God can give us disease to punish us for our wrongdoing. Sometimes we can have diseases due to our disobedience and it may be genetic. So much sugar can cause diabetes, so we should limit the amount of our sugar in talk. What should prevail in our hearts is the peace of Christ. In those times, there are problems, it is the peace of Christ that should prevail. When anxiety, problems, and many other things can take any peace come, it is the peace of God that should prevail.
As you mentioned, there are various types of diseases and some of which can be a result of our choices or actions.
It's essential to be mindful of our health and the decisions we make, such as limiting sugar intake to prevent diabetes. In times of difficulty, let the peace of Christ prevail in our hearts and minds.