Many terms are specific to the practice of herbal medicine. The terms on the following list are not a comprehensive list of herbal actions, but are meant to help explain a few of the basic terms associated with Western herbalism. Other systems, such as traditional Chinese medicine (TCM) and Ayurveda, which are based on completely different concepts, have a terminology all their own.
Adaptogens are compounds found in herbs that can help your body adapt to and defend against the effects of physical stress, such as extreme cold or sleep deprivation. Scientists do not yet understand exactly how adaptogens work. Some theories suggest that they may help control the release and effects of stress hormones and modulate blood glucose levels, which in turn counteracts the damaging effects of stress on your body. Common adaptogenic herbs are ginseng (Panax spp.), eleuthero (Eleutherococcus senticosus), and reishi mushroom (Ganoderma lucidum).
Alteratives are herbs used to gradually bring about fundamental changes in health. Often, they are used to treat chronic skin conditions or autoimmune diseases. Researchers are unsure of how they work, but scientific studies offer a number of possibilities. Some alteratives, such as burdock (Arctium lappa), nettle (Urtica dioica), and yellow dock (Rumex crispus), seem to improve the efficiency of basic body functions, such as digestion, assimilation of nutrients, and elimination of wastes. Others, such as echinacea (Echinacea spp.), benefit your immune system. As with many herbs, alteratives probably work by a combination of effects.
Analgesics and anodynes are pain relievers. Examples include willow bark (Salix spp.), poplar (Populus spp.), and devil’s claw (Harpagophytum procumbens).
Anticatarrhal herbs help your body eliminate excess mucus. Many of these herbs contain astringent tannins; others are rich in volatile oils. Examples include elecampane (Inula helenium), hyssop (Hyssopus officinalis), and thyme (Thymus spp.).
Anticholesterolemic herbs, such as green tea (Camellia sinensis), lower cholesterol levels by either inhibiting your body’s production or absorption of cholesterol or by enhancing its excretion.
Anti-inflammatory agents reduce swelling and redness associated with inflammation. Anti-inflammatory herbs for internal use include turmeric (Curcuma longa), meadowsweet (Filipendula ulmaria), wild yam (Dioscorea villosa), and devil’s claw (Harpagophytum procumbens). Anti-inflammatory herbs used externally include St. John’s wort (Hypericum perforatum) and arnica (Arnica montana).
Antimicrobial herbs contain compounds that kill pathogens, or disease-causing organisms. Herbs with antibacterial, antifungal, and antiviral actions are all considered antimicrobial. Some antimicrobials, such as echinacea (Echinacea spp.), also stimulate your immune system. Research has shown that cranberry (Vaccinium macrocarpon) and related plants can prevent urinary tract infections because they discourage the attachment of bacteria to the walls of your urinary tract.
Antioxidants protect your body from the damaging effects of free radicals and may help protect against various degenerative diseases.
Antirheumatic herbs are helpful in the treatment of arthritis and other degenerative conditions that affect connective tissue. These herbs include devil’s claw (Harpagophytum procumbens), turmeric (Curcuma longa), nettle (Urtica dioica), boswellia (Boswellia serrata), and feverfew (Tanacetum parthenium).
Antispasmodic herbs relax muscles and ease muscle spasms and cramps. Some may alleviate muscle tension throughout your body, while others are specific to certain types of muscle tissue or organ systems. Many are also relaxing nervines, easing psychological tension as well. Chamomile (Matricaria recutita) and valerian (Valeriana officinalis) relax spasms in your digestive tract and calm nervous tension. Mullein (Verbascum thapsus) relieves spasms in your respiratory tract. Valerian helps ease muscle tension throughout your body.
Astringents tighten and tone tissues, especially mucous membranes, usually due to their tannin content. They also help dry excess secretions. They can be taken internally to treat conditions such as diarrhea or externally, as styptics, to stop bleeding. Examples include yarrow (Achillea millefolium) and witch hazel (Hamamelis virginiana).
Bitter herbs stimulate digestion, enhancing the flow of digestive juices and peristalsis, the muscle action that moves food through your digestive tract. Some bitter salad greens are eaten before a meal to aid digestion. Gentian (Gentiana lutea), mugwort (Artemisia vulgaris), and dandelion leaf (Taraxacum officinale) are bitter herbs.
Carminative herbs relieve gastrointestinal stress. They also enhance peristalsis, the action that moves food and gas through your digestive tract. Many are also popular culinary herbs and spices; those include thyme (Thymus spp.), dill (Anethum graveolens), caraway (Carum carvi), and ginger (Zingiber officinale).
Cholagogue herbs act by stimulating the flow of the digestive enzyme bile, which aids the digestive process. Dandelion root (Taraxacum officinale) is a cholagogue.
Demulcent herbs soothe and protect irritated or inflamed tissue and are often specific to one or more body systems. For instance, marshmallow leaf (Althaea officinalis) is a urinary tract demulcent; marshmallow root and licorice (Glycyrrhiza glabra) are digestive system demulcents. Respiratory demulcents include mullein (Verbascum thapsus), licorice, and marshmallow root.
Diaphoretic herbs induce perspiration, helping to “break” a fever and improve circulation. They’re also used to treat colds and flu. Examples include yarrow (Achillea millefolium), boneset (Eupatorium perfoliatum), and ginger (Zingiber officinale).
Diuretic herbs stimulate the flow of urine and help your body eliminate excess fluid. Some also have antiseptic actions in your urinary tract, making them useful for urinary tract infections. These could be too irritating for people with kidney problems, however. Examples include dandelion leaf (Taraxacum officinale), parsley (Petroselinum crispum), and saw palmetto (Serenoa repens). Juniper (Juniperus communis) is a diuretic with strong antiseptic properties.
Emmenagogue is a term that once referred to herbs that induced menstrual flow, but it has come to be used more loosely to describe herbs that benefit female reproductive health. Herbs thought to stimulate sluggish menstrual flow include yarrow (Achillea millefolium) and feverfew (Tanacetum parthenium). Black cohosh (Cimicifuga racemosa) and vitex (Vitex agnus-castus) are believed to help normalize the function of the female reproductive system.
Expectorant herbs promote the elimination of mucus from your lungs. Stimulating expectorants, which commonly contain volatile oils, saponins, or alkaloids, include horehound (Marrubium vulgare), elecampane root (Inula helenium), and mullein leaves (Verbascum thapsus).
Galactogogue herbs help stimulate the flow of milk in nursing mothers. Galactogogues include dill (Anethum graveolens) and fennel (Foeniculum vulgare). Both are also classic remedies for infant colic.
Hepatic herbs help improve liver function. Examples include milk thistle (Silybum marianum) and licorice (Glycyrrhiza glabra).
Hypnotic herbs induce sleep and can be taken to treat insomnia. Examples include hops (Humulus lupulus), valerian (Valeriana officinalis), and passionflower (Passiflora incarnata).
Hypotensive herbs help lower blood pressure. These include hibiscus (Hibuscus sabdariffa), hawthorn (Crataegus laevigata), and valerian (Valeriana officinalis).
Immunomodulator herbs affect immune function. Some, such as echinacea (Echinacea spp.), stimulate immune cells such as phagocytes, which fight infection by destroying invading pathogens. Others are the subjects of ongoing clinical research to determine and clarify their activity. Among these herbs are astragalus (Astragalus membranaceus), shiitake mushroom (Lentinus edodes), and reishi mushroom (Ganoderma lucidum).
Laxative herbs stimulate the action of your bowels. Bulk-forming laxatives are high in fiber; they include psyllium (Plantago ovata) and flaxseed (Linum usitatissimum). Stimulant laxatives chemically induce peristalsis; they include senna (Senna alexandrina), cascara sagrada (Rhamnus purshiana), and buckthorn (R. cathartica). High doses of these laxatives are not recommended for long-term use. Mild laxatives that work through other actions (by stimulating bile flow, for example) include dandelion root (Taraxacum officinale) and yellow dock (Rumex crispus).
Nervine herbs affect the function of your nervous system. Nervines can be relaxing, tonic, or stimulating. Relaxing nervines include valerian (Valeriana officinalis), passionflower (Passiflora incarnata), and chamomile (Matricaria recutita). Tonic nervines include oats (Avena sativa) and St. John’s wort (Hypericum perforatum). Herbs that stimulate your nervous system include caffeine-containing plants, such as tea (Camellia sinensis), as well as volatile oil–rich plants, such as rosemary (Rosmarinus officinalis) and peppermint (Mentha × piperita).
Rubefacients are herbs that, when applied externally, draw blood to an area for a localized warming effect. They include ginger (Zingiber officinale), black mustard (Brassica nigra), and chile pepper (Capsicum annuum).
Vasodilator herbs dilate blood vessels, which is useful in the treatment of cardiovascular conditions such as high blood pressure. Examples include ginkgo (Ginkgo biloba) and feverfew (Tanacetum parthenium).
Vulnerary herbs speed the healing of wounds. Examples include aloe (Aloe vera), comfrey (Symphytum officinale), calendula (Calendula officinalis), and St. John’s wort (Hypericum perforatum). Some vulnerary herbs can also be used internally.