The primary causes always lie in the spiritual, mental. On the one hand, these can be belief patterns. Common belief patterns are based on the "medical" definitions of "diseases", as soon as these definitions are seen as truth.
Unfortunately, it is usually overlooked that the "disease" symptoms are healthy reactions of the body. Understanding them instead of fighting them allows to recognize it as a temporary condition in which self-healing takes place.
Or the causes are traumatic experiences. Fear is always involved. Allopathic medicine also - or even mostly - sees causes on the physical level. However, these are effects of mental activities or beliefs. Also bacilli can be seen as cells of a spiritual being that can go into resonance with a part of your being.
Here is a quote from the book “Initiation“ by Elisabeth Haich, Drei Eichen Verlag:
"The word 'Ayurvedic' means a person who is initiated into the AyurVedas. Vedas are the sacred books of Indians, the highest philosophy on earth. The Vedas consist of different parts. AyurVeda is the science of health, it contains all the secrets of the human body, diseases, cures and staying healthy. These initiates ... also knew that the cause of diseases are myriads of invisible little living beings, today they are called bacteria, but they also knew that the bacteria are the cells of the invisible body of a demonic spirit, which, however, is not researched at all in the West, apart from individual initiates, such as Paracelsus, for example. The evil spirit takes possession of one or more human beings, it penetrates the human being with its body, and if this human being agrees with the vibrations of the evil spirit, he becomes ill. But there are also always those people who do not resonate with the vibrations of the demon, they do not get sick, they are - as western science calls it - immune".
In this quote no distinction is made between bacilli and bacteria. Mainly bacteria - not only for me - are considered useful helpers and natural components of our physical body. They actively participate in the metabolic process. There are bacteria that use nitrogen from the air we breathe to produce protein building blocks.
The great healer Dascaloswho worked in Cyprus, says that "all diseases have karmic causes".