Let’s start with cardiovascular diseases (CVD) as they are one of the top causes of death worldwide. One metadata study in 2018 reviewed the effects of essential oils on risk factors of CVD which include hypertension (high blood pressure), diabetes, fatty liver and an abnormally high amount of lipids in the blood (dyslipidemia). Evidence showed that essential oils improved lipid balance, liver function, reduced blood pressure, the onset of diabetes, relaxed blood vessels and inhibited blood clots. The studies reviewed included those on animals and humans. The study concluded that essential oils may be promising therapeutic agents for CVDs.
In another systematic review published in 2020, herbal essential oils were shown to reduce coronary artery disease, heart attack, abnormal heart rhythms, heart failure, vascular diseases and many others. However, these studies were conducted in mice, rats and rabbits.
Although results of animal testing aren’t an indication that the same result will be obtained in humans, it can suggest possibilities for further research.
One 2012 study measured the blood pressure of subjects at home that inhaled a blend of lavender, ylang ylang, marjoram and neroli. The experimental group’s blood pressure was significantly reduced, compared to the placebo and control group. The effects were seen in as little as ten minutes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521421/
Another study in 2017 used inhalation of marjoram essential oil and observed that blood pressure and heart rate decreased in this group but not the control group.
A study was conducted in 2017 on 40 ICU patients who had open heart surgery and after inhaling lavender, their heart rate and blood pressure was significantly reduced. This is important since many patients experience abnormal or high heart rates and high blood pressure due to the stress and pain of their surgeries.
For hemorrhoids, myrtle essential oil was reviewed in 2017 and found to significantly improve bleeding, pain, irritation and itching, even in patients who did not respond to current chemical ointments.