Hawthorn herb is an ingredient in traditional Chinese medicine; herbalists prescribed it as a poison antidote as well as a treatment for scurvy. Native Americans used it to treat conditions such as heart, stomach and kidney problems. American doctors prescribed it to treat breathing and heart problems during the 1800s.
Hawthorn herb contains plant chemicals that improve the flow of blood and protect blood vessels against damage from free radicals, which are compounds inside the body that damage cells and contribute to health problems. Hawthorn is used to treat conditions such as high blood pressure and heart disease. It also helps lower cholesterol.
Hawthorn occasionally causes side effects such as stomach upset, headache and erratic heartbeat. The herb is not considered safe for children, pregnant women or nursing mothers, according to the University of Maryland Medical Center. Hawthorn may interfere with certain medications. Patients should talk to their doctors before using hawthorn.