What herbal medicine cannot do — and when to stop

Herbal medicine cannot cure cancer, reverse diabetes, or substitute for antibiotics in serious infection. It cannot fix structural problems — a torn ligament, a slipped disc, a cataract. It works at the margins: easing symptoms, supporting recovery, preventing mild problems from worsening. That is still valuable, but only if you recognise the limits.

Red flags that mean stop and see a doctor: any chest pain, difficulty breathing, or rapid heartbeat. Any severe abdominal pain, vomiting blood, or black stools. Any lump that grows or changes. Any headache that is sudden, severe, or different from usual. Any wound that reddens, swells, or streaks. Any fever above 38.5°C that lasts more than 48 hours. Any symptom in a child under two. Any worsening despite treatment. Herbal medicine is not a replacement for diagnosis. Get the diagnosis first, then decide if herbs have a role.

Some conditions respond well to herbs as an adjunct. Mild to moderate anxiety and insomnia: lemon balm, chamomile, passionflower, valerian. Indigestion and bloating: peppermint, fennel, ginger. Coughs and colds: thyme, elderflower, echinacea (though evidence for echinacea is mixed). Minor skin wounds: calendula, plantain, comfrey. Menopausal hot flushes: sage, black cohosh. Mild depression: St John's wort (but only if not on other medication). These are the evidence-backed uses. The rest is speculation or tradition that has not held up in trials.

The best use of herbal medicine is preventive and tonic. Nettle tea is rich in minerals; drink it in spring to offset winter depletion. Elderberry syrup reduces the severity and duration of colds if taken at the first sign. Hawthorn supports cardiovascular health in older adults. Calendula salve on a small cut stops it becoming a large problem. These are not dramatic interventions. They are quiet, cumulative, sensible. That is what herbal medicine does well. If you want drama, you want pharmaceuticals. If you want a living pharmacy that asks little and gives steadily, you want herbs.