Herbal Actions
The way an herb affects the body—the nature of its action—helps bring about balance and relieve symptoms for certain ailments. Herbs have many different actions. A knowledge of these particular actions, along with a sense of the organs and tissues where they primarily act, helps you to effectively choose which one or more of several herbs to use in your remedies.
Antibiotic– Antibiotics are agents that destroy or inhibit the growth of viruses and bacteria, either by directly destroying germs, or by supporting the body’s own immune responses.
Anti-inflammatories – These herbs reduce inflammation and relieve the associated swelling and pain.
Antiseptic – These herbs have the power to destroy or prevent the growth of bacteria, and to retard the decay of tissue and formation of pus.
Carminative – Herbs that have a stimulating effect on the gastrointestinal mucus membranes because of their essential oils, and are used to aid digestion and expel wind from the stomach and bowels.
Demulcent – When taken internally, these herbs help to soften, relieve, and protect irritated or inflamed tissue, particularly the mucus membranes. 
Diuretic – Herbs that increase the flow of urine, usually rich sources of bio-available minerals.
Emetic – Herbs that are used to induce vomiting, and to help the body clear obstructions and offensive material from the stomach.
Expectorant – Herbs that aid production and elimination of mucus from the throat and lungs.
Hemostatic – Herbs that arrest internal bleeding or hemorrhaging.
Vulnerary – Herbs that promote the healing of fractures, cuts, wounds, and burns by protecting against infection, and by stimulating cellular renewal.
A couple of examples of looking at herbal actions:
https://blog.mountainroseherbs.com/understanding-herbal-actions
http://www.foundationsofherbalism.com/pdf/actions.pdf
There are no fixed methods to apply to the human predicament, there is no single all-pervasive rule to follow, since medicine is not a science but an art. Michael Moore, herbalist