What does urticaria commonly refer to?

Urticaria is a medical term that specifically refers to hives, which are raised, itchy welts on the skin that can vary in size and often result from an allergic reaction. The condition is characterized by the sudden appearance of welts, which can be accompanied by redness and swelling. When mast cells in the skin release histamine and other inflammatory chemicals, it causes fluid to leak from blood vessels into the surrounding tissues, leading to the symptoms associated with hives.

In contrast, the other options pertain to entirely different medical conditions. Morning sickness is related to nausea and vomiting experienced during pregnancy. Severe dehydration involves a significant loss of body water and electrolytes, leading to a range of health complications. Kidney stones are hard deposits made of minerals and salts that form inside the kidneys, and their symptoms are quite different from those of urticaria. Thus, understanding the specific terminology and pathology of urticaria reinforces its identification as hives in medical discussions.