Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin culex meaning "gnat"). The word "mosquito" (formed by mosca and diminutive -ito) is Spanish and Portuguese for "little fly". Mosquitoes have a slender segmented body, one pair of wings, one pair of halteres, three pairs of long hair-like legs, and elongated mouthparts. The mosquito life cycle consists of egg, larva, pupa, and adult stages. Eggs are laid on the water surface; they hatch into motile larvae that feed on aquatic algae and organic material. These larvae are important food sources for many freshwater animals, such as dragonfly nymphs, many fish, and some birds such as ducks. The adult females of most species have tube-like mouthparts (called a proboscis) that can pierce the skin of a host and feed on blood, which contains protein and iron needed to produce eggs. Thousands of mosquito species feed on the blood of various hosts ⁠— vertebrates, including mammals, birds, reptiles, amphibians, and some fish; along with some invertebrates, primarily other arthropods. The mosquitos saliva is transferred to the host during the bite, and can cause an itchy rash. In addition, many species can ingest pathogens while biting, and transmit them to future hosts. In this way, mosquitoes are important vectors of parasitic diseases such as malaria and filariasis, and arboviral diseases such as yellow fever, Chikungunya, West Nile, dengue fever, and Zika.
Costochondritis, also known as chest wall pain syndrome or costosternal syndrome, is a benign inflammation of the upper costochondral (rib to cartilage) and sternocostal (cartilage to sternum) joints. 90% of patients are affected in multiple ribs on a single side, typically at the 2nd to 5th ribs. Chest pain, the primary symptom of costochondritis, is considered a symptom of a medical emergency, making costochondritis a common presentation in the emergency department. One study found costochondritis was responsible for 30% of patients with chest pain in an emergency department setting.The exact cause of costochondritis is not known; however, it is believed to be due to repetitive minor trauma, called microtrauma. In rarer cases, costochondritis may develop as a result of an infectious factor. Diagnosis is predominantly clinical and based on physical examination, medical history, and ruling other conditions out. Costochondritis is often confused with Tietze syndrome, due to the similarity in location and symptoms, but with Tietze syndrome being differentiated by swelling of the costal cartilage. Costochondritis is considered a self-limited condition that will resolve on its own. Treatment options usually involve rest, pain medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), ice, heat, and manual therapy. Cases with persistent discomfort may be managed with an intercostal nerve blocking injection utilizing a combination of corticosteroids and local anesthetic. The condition predominantly affects women over the age of 40, though some studies have found costochondritis to still be common among adolescents presenting with chest pain. : 388

Presentation
Costochondritis typically presents unilaterally (one side), which is typically the left side.