We have seen same disease sometimes get cured through different systems like allopathy, homoeopathy, Ayurveda, unani etc. and also through drugless therapy like yoga therapy, pranic healing, reiki therapy, magnet therapy etc. and all these systems have different theories that cures the same diseases. Then question comes which system is scientific or how truly diseases get alleviated.
In modern healthcare system, allopathy has more scientific approach with advanced pathological tests and digital technological image processing to arrive at right diagnosis or finding the root cause of the disease. Whereas, other systems like homoeopathy, Ayurveda, unani etc. depend more on analytical study of the symptoms and prescribe the medicine. Success rate and time taken to recover might differ but how same disease get cured by different theory of different therapy is to be understood. It can be possible only if there is one master theory that connect all theories in deeper level like different parts or organs functions uniformly of a same body.
Placebo and nocebo theory says, sometimes diseases get cured if someone has faith in doctor or drug even diagnosis is wrong or medicine content is not there in pills. So, there is an unknown factor playing a role in these cases beyond scientific reasoning. We have to take both science and faith into consideration to arrive at correct conclusion. Now medical science is coining a word, psychosomatic, i.e body and mind are not two different entities rather either side of a same coin. Thus, if body is affected by disease, thereby mind will also be affected and vice versa.
Of course, scientific laws are more applicable in matter or physical aspect rather than subtle mental phenomena in which faith or other unknown factors like; life style, attitude, heredity, genetic influences are more active. In the presence of consciousness, body and mind functions and when it leaves the body it cannot heal itself. That means, consciousness and in turn, prana or life energy is the prime factor, that is essential in healing with or without medicine (faith/unknown factors).
Thus, apart from scientific medicinal approach, diseases can be cured in many of the cases where this life energy can be brought in a balanced state and healing happens through natural means. Faith is one of the factors that raises the level of prana or energy for effective healing. Preserving prana through various means such as managing life style, balanced diet and nutrition, listening to the signals of the body and act accordingly and of course, through various yogic discipline, even chronic diseases can be cured or cared without or with drug.