Plant of horse radish
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Horseradish, known botanically as Armoracia rusticana, has been used for centuries for medicinal purposes, and only later became a spicy substance used in foods. Horseradish contains volatile oils that are similar to those found in mustard. In test tubes, the volatile oils in horseradish show antibiotic properties, which likely is why it is effective in treating throat and upper respiratory tract infections, according to the Blue Shield of California website. The oil has also been shown to kill the bacteria that can cause urinary tract infections. However, horseradish can produce some side effects.

Mucous Membrane and Skin Irritation

Horseradish is a spicy substance that belongs to the mustard family, which can irritate sensitive or delicate areas of the body. For example, horseradish can cause irritation and/or burning to multiple sites that involve mucous membranes. These include the inner lining of the mouth, stomach and intestines, eyes and urinary tract, according to Drugs. com and If you happen to apply horseradish directly to the skin or if it comes in contact with your eyes, it may result in irritation as well as possibly produce eruptions on the skin.

Gastrointestinal Reactions

Another side effect that you may experience with horseradish is an upset stomach. explains that horseradish toxicity from consuming large amounts can result in bloody vomiting and diarrhea. Additionally, horseradish can irritate the pharynx and esophagus, and aggravate stomach ulcers, according to If you begin experiencing these adverse reactions you should seek immediate medical care.

Thyroid Dysfunction

If you have a thyroid condition you should not use horseradish until you first discuss it with your doctor. According to, horseradish may impair thyroid function by interfering with the production of hormones produced by the thyroid. Additionally, if you already have been diagnosed with hypothyroidism you should avoid horseradish so that your thyroid hormone levels do not drop even lower.

Pregnancy and Breastfeeding

If you are pregnant or planning on breastfeeding, it is imperative that you avoid horseradish, according to and Horseradish is capable of causing a miscarriage, and has even been used to induce abortions. Additionally, certain toxic chemicals within horseradish end up being excreted during lactation, which is why it should be avoided if you are breastfeeding.


Horseradish should be avoided by people who have been diagnosed with hypothyroidism, gastrointestinal conditions, stomach or intestinal ulcers, or inflammatory bowel disease, according to the Blue Shield of California website. Finally, individuals with kidney disorders or disease also should avoid horseradish so as not to exacerbate existing conditions.