Lower back problems (related to the musculoskeleton) and rheumatism. Horsetail is found beneficial in dropsy, gravel and kidney affections. The ashes of the plant are considered very valuable in acidity of the stomach, dyspepsia, etc. Besides being useful in kidney and bladder trouble, a strong decoction acts as an emmenagogue; being cooling and astringent, it is of efficacy for haemorrhage, cystic ulceration and ulcers in the urinary passages. The decoction applied externally will stop the bleeding of wounds and quickly heal them, and will also reduce the swelling of eyelids. Horsetails have an unusual chemistry compared to most other plants.