A brief sudden change in a normally constant quantity: a pulse of current; a pulse of radiation. b. Any of a series of intermittent occurrences characterized by a brief sudden change in a quantity.
Some pregnant women experience a metallic taste in their mouth during the early stages of pregnancy, because of the hormone changes. It's also fairly common to crave certain foods, or go off certain foods, and have a heightened sense of smell. Learn more about the signs and symptoms of pregnancy.
All the above medications have side effects that include producing metallic taste in mouth. Oral problems like periodontitis and gingivitis can also cause this taste. It can be the symptom or warning sign for underlying disease like cancer, ulcer, food allergy and lichen planus. Many kinds of poisoning like lead poison, mercury poison, iodine poison, cadmium poison, selenium toxicity, increased copper level can produce metallic taste in your mouth.