There are some people who should definitely be more cautious when it comes to using herbal remedies. One group is those with high blood pressure. While some herbs can be used to effectively combat and ease high blood pressure, others can make it worse.
Luckily, the list isn’t too long, but there are some to note. Licorice and ephedra are the two with a significant amount of evidence linking them to high blood pressure. Other herbs are also suspected to have properties that can raise blood pressure, but significant research has not been doneto confirm this. Still, people with high blood pressure may want to avoid these: Ephedra, licorice, anise seed, St. John’s wort, capsaicin, guarana, ginseng, parsley, blue cohosh, vervain, coltsfoot, gentian, bayberry and chasteberry.
A second group of people are those with hypotension — low blood pressure. Many herbs can lower blood pressure, normally a good thing, but potentially harmful for someone with hypotension. The evidence is not great for many, but these herbs pose a risk: garlic, hawthorn, olive leaf, onion, hibiscus, Indian snakeroot, European mistletoe, reishi mushrooms and coleus forskohlii.
A big group of people who always have to be careful is that made up of those with kidney failure or disease. The main function of the kidneys is to clear waste products from the body. When you suffer from renal disease, your body is not as effective with dealing with waste products or minor toxins. Unfortunately, this means that a lot of substances, including herbs, are not safe for use.
One class of herbs is suspected to have damaging effects on kidney patients: diuretics. Because diuretics force more waste from the body, they can increase the speed at which the kidneys have to work to clean the waste products. When the kidneys don’t work properly, this aggravates them, increasing symptoms and moving up how soon dialysis will be needed. For this reason, diuretics and diuretic herbs like bucha leaves, juniper berries and parsley should be avoided by people suffering from kidney disease.
Some others not recommended in those with kidney disease: wormwood, periwinkle, autumn crocus, horse chestnut, alfalfa, aloe, bayberry, rhubarb, dandelion, ginseng, ginger, nettle, noni juice, licorice, capsaicin, blue cohosh, coltsfoot and horsetail.
The only kidney-related disorder that may actually be benefited by herbal therapies seems to be kidney stones. In this case, herbal therapies may actually help prevent or ease the presence of stones.
In any event, this information is meant to show that herbal therapies, while natural, can still be an issue for people with certain health issues.