The leaves and stems are very hairy with non-stinging hairs, and in most subspecies, also bear many stinging hairs (trichomes or spicules), whose tips come off when touched, transforming the hair into a needle that can inject several chemicals causing a painful sting or paresthesia, giving the species its common names: stinging nettle, burn-nettle, burn-weed, or burn-hazel. Taxonomy
The taxonomy of Urtica species has been confused, and older sources are likely to use a variety of systematic names for these plants. Formerly, more species were recognised than are now accepted. However, at least six clear subspecies of U. dioica are described, some formerly classified as separate species:

U. dioica subsp. dioica (European stinging nettle), from Europe, Asia, and northern Africa, has stinging hairs. U. dioica subsp. galeopsifolia (fen nettle or stingless nettle), from Europe, does not have stinging hairs. U. dioica subsp. afghanica, from southwestern and central Asia, sometimes has stinging hairs or is sometimes hairless. U. dioica subsp. gansuensis, from eastern Asia (China), has stinging hairs. U. dioica subsp. gracilis (Ait.) Selander (American stinging nettle), from North America, has stinging hairs and is monoecious. U. dioica subsp. holosericea (Nutt.) Thorne (hoary stinging nettle), from North America, has stinging hairs and is monoecious.Other species names formerly accepted as distinct by some authors but now regarded as synonyms of one or other subspecies include U. breweri, U. californica, U. cardiophylla, U. lyalli, U. major, U. procera, U. serra, U. strigosissima, U. trachycarpa, and U. viridis.
Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancreatitis. Signs and symptoms of pancreatitis include pain in the upper abdomen, nausea and vomiting. The pain often goes into the back and is usually severe. In acute pancreatitis, a fever may occur, and symptoms typically resolve in a few days. In chronic pancreatitis weight loss, fatty stool, and diarrhea may occur. Complications may include infection, bleeding, diabetes mellitus, or problems with other organs.The two most common causes of acute pancreatitis are a gallstone blocking the common bile duct after the pancreatic duct has joined; and heavy alcohol use. Other causes include direct trauma, certain medications, infections such as mumps, and tumors. Chronic pancreatitis may develop as a result of acute pancreatitis. It is most commonly due to many years of heavy alcohol use. Other causes include high levels of blood fats, high blood calcium, some medications, and certain genetic disorders, such as cystic fibrosis, among others. Smoking increases the risk of both acute and chronic pancreatitis. Diagnosis of acute pancreatitis is based on a threefold increase in the blood of either amylase or lipase. In chronic pancreatitis, these tests may be normal. Medical imaging such as ultrasound and CT scan may also be useful.Acute pancreatitis is usually treated with intravenous fluids, pain medication, and sometimes antibiotics.