The horse chestnut, or Aesculus hippocastanum, is a deciduous tree of Balkan origin that bears a smooth, round nut that is toxic if eaten raw but that does have medicinal qualities. It is related to the Castanea sativa tree that bears the edible sweet chestnuts served during the holiday season.
The trees have a life span of up to 300 years and can grow to be 100 feet tall. The nuts on the horse chestnut form inside a round, prickly fruit, while the sweet chestnut's pod looks more like a porcupine. Outside the pod, both nuts look similar. The edible chestnuts have a little tassel on one end, while the horse chestnuts are smooth all around.
Horse chestnut is used as an herbal medicine in some cultures ? mostly to treat circulation problems, fever and enlarged prostate. It is usually administered as an extract from the processed nuts and leaves; however, the medical community in the United States advises caution because of the toxicity factor.
The extract of horse chestnut can interfere with blood clotting, cause hypoglycemia, or low blood sugar, and irritate the gastrointestinal tract. Physicians stress that users of horse chestnut do so in moderation. Pregnant women, those with liver conditions and anyone on anticoagulant or diabetic medications are advised against taking horse chestnut extract, according to MedlinePlus.