The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below. Acne, addiction, allergies, Alzheimer's disease, antibacterial, anticonvulsant, antifungal, antiviral, asthma, autonomic dysfunction, back pain, bereavement/grief, bladder infections, boils, bronchitis, burns, chronic bronchitis (prevention and treatment), chronic pain, circulation, cognitive performance enhancement, common cold, confidence boosting, coping skills, digestion disorders, exercise recovery, exhaustion, fever, gas, Guillian-Barre syndrome (symptom relief), headache, high blood pressure, hormonal disorders, immune system stimulant, impatience, impotence, improving circulation, indigestion, infections (intravenous/Hickman line), inflammation, insect bites, irregular heartbeat, irritability, joint pain, labor pain, laryngitis, liver disorders, loss of appetite, maternal comfort during labor, memory enhancement, menstrual cramps, motion sickness, mucositis, muscle pain, nausea, nerve pain, pain, palliative care, panic attacks, pimples, prevention of respiratory tract infections, psoriasis, psychosomatic illness, reducing swelling after injuries, relieving menstrual symptoms, restlessness, rheumatic disorders, seizure disorder, sexually transmitted diseases, skin infections, skin rash in bone marrow transplant patients (engraftment syndrome rash), smoking withdrawal symptoms, spasms, sprains and strains, stimulation of digestion, stomach complaints, sunburn, study performance (math tasks), swelling, tendonitis, vaginitis, yeast infections.
Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.
Skin rash (dermatitis) from direct contact with various essential oils has been reported in humans, and skin irritation can develop with regular use. Peppermint and eucalyptus oils may burn the skin if applied at full strength. With the possible exception of lavender, essential oils should be diluted with a base oil before use to avoid skin irritation. Severe phototoxicity/photosensitivity (skin sensitivity to light) may occur, particularly with oil of bergamot. Vapors from aromatherapy may irritate the eyes, and patients are advised to keep their eyes closed while inhaling aromatic vapors.
Allergy may occur with use of essential oils, and may be due to contamination, or to constituents of the herb(s) from which the oil is derived. In cases of suspected skin allergy, some aromatherapists will place a single drop of oil on the skin to see if a reaction occurs over 24 hours. Individuals who have difficulty breathing with the use of aromatherapy should seek medical attention before attempting aromatherapy again.
Oils applied to the skin or inhaled through the nose and mouth can be absorbed into the body and can have systemic effects. There are reports of agitation, drowsiness, nausea, and headache with the use of aromatherapy. Some oils are thought to have toxic effects on the brain, liver and kidney, or to increase the risk of cancer with long-term use. Aromatherapies that may increase sedation or drowsiness, such as lavender or chamomile, may add to the effects of drugs, herbs, or supplements that also cause fatigue or sedation. Caution is advised in people who are driving or operating heavy machinery.
Essential oils may be toxic if taken by mouth, and should not be swallowed. Fragrances may contain unknown and potentially toxic contaminants. There are reports that lead emission may occur from the burning wick of aromatherapy candles, although long-term health effects are not clear.
Based on human use, sage, rosemary, and juniper oils may cause the uterus to contract when taken in large amounts. Due to these reports, and lack of reliable safety data, the use of these oils is discouraged during pregnancy.
Infants and young children may be especially sensitive to the effects and side effects of essential oils. Peppermint oil is not recommended in children under the age of 30 months. It is suggested to consult a qualified healthcare professional before using aromatherapy in children.