WITH WHICH DISEASES CAN HERBAL MEDICINE DEAL?

Herbal medicine is a complete system of treatment as well as approach to the achievement of health. It aims to encourage and support natural self-healing mechanisms, and by working from the roots of imbalance the patient regains health and so the symptoms disappear. Under qualified treatment, this approach can be of benefit whatever may be obtained in certain illnesses. It is the person who is treated, rather than the disease.
Is there any specific demarcation between the herbs that we eat and those called medicinal herbs?
There is no such demarcation. In fact, under Ayurveda, both foods and herbs are considerate to be made up of the same five basic elements called Pancha-maha-bhutas, viz. earth, water, energy, air, and ether. Different entities have different quantities and combinations of these five elements.