Summer brings about a number of things: sunshine and longer days, green trees, running outdoors, blooming flowers, sandals and short sleeves, and lots of pollen. 

One of my favorite herbs for aliments that come from changing seasons is Stinging Nettle (Urtica dioica). Encountered in the wild, Stinging Nettle is generally perceived to produce a less than appealing effect on the body. The stem and leaves of this plant are covered with tiny hairs that contain histamine, acetylcholine, formic acid and serotonin which produce a burning sensation when the hairs come in contact with bare skin. However aside from this, Stinging Nettle has a wealth of benefit to your body. According to Herbal Medicine: From the Heart of the Earth, Stinging Nettle is highly beneficial as a spring tonic. It supports the immune system, circulation, the urinary, digestive and respiratory tracts as well as the endocrine system. It provides whole body nourishment at a time when the environment and our bodies are going through changes.

Seasonal allergies can be extremely bothersome. Stinging Nettle reduces the symptoms of allergies by decreasing the amount of histamine produced in response to an allergen. It is most effective when the dried leaves are decocted into a strong tea; the steam from the tea can also alleviate bronchial constriction caused by asthma. Did you know that Stinging Nettle has a unique use for pain as well?

My classmate recently told me that he used Stinging Nettle for his joint pain. After running long distances he would use a branch of fresh Stinging Nettle and brush the leaves on his aching knee joints. This helped reduce the pain he was feeling. The idea is that when your body feels the sting from the plant, it actually decreases the original feelings of pain. According to the University of Maryland, scientists believe that Stinging Nettle accomplishes this by decreasing the levels of inflammatory chemicals in the body and interfering with the way the body transmits pain signals. The neurotransmitter, Substance P, is exhausted and pain perception is reduced.

In physical medicine, this idea is known as the Gate Control Theory of Pain. According to theorists Ronald Melzack and Patrick Wall, there are two types of fibers that carry pain sensation from the site of an injury to the dorsal horn of the spinal cord: thin pain receptive fibers and larger fibers that detect touch, pressure and vibration. When the signals from these thin and large fibers exceed a critical level, we feel pain. Within this system, there are transmission cells and inhibitory cells. The inhibitory cells can inhibit transmission cells by closing the pain "gate"; the transmission cells act as the gate. The thin fibers impede the inhibitory cells which lead to an open gate, and the resulting pain. Larger diameter fibers excite the inhibitory cells which close the gate, leading to a decreased pain sensation. This is why we tend to rub an injured finger or a stubbed toe. The rubbing sensation decreases the ability to feel the initial cause of the pain. This explains why pain would be decreased when using Stinging Nettle on a previously injured site, yet would be rather painful under normal circumstances.

Herbs and plants have a number of diverse properties, in the case of Stinging Nettle, this plant is a useful tool in treating allergies and pain. Although you might not initially think of an alternate use like pain management, it’s important to think outside the box when using herbs. Much like the treatment of patients in Naturopathic Medicine, we shouldn’t place patients in “category” based on symptoms; restricting the use of a plant to one condition can hinder our ability to see the plant for all of its unique uses.
 
References:
http://www.umm.edu/altmed/articles/stinging-nettle-000275.htm
Herbal Medicine: From the Heart of the Earth, Dr. Sharol Marie Tilgner http://en.wikipedia.org/wiki/Gate_control_theory_of_pain#Gate_control