Blood cells contain oxygen carrying hemoglobin. When blood breaks down, iron is released and causes a metallic taste. Bleeding can be from the gums, sinuses or nose. The taste can get especially bad when someone has post nasal drip and the dried blood sticks to the back of the throat. If bleeding gums are the cause, there is often bad breath associated with the bad taste.
Another uncommon reason for a metallic taste is due to small electric currents in the mouth. When two types of metals are used in two different dental fillings a battery can be created. Some believe that it's due to the mercury leakage from dental silver/mercury fillings.
Many oral or IV medications such as thyroid medicine, penicillin, and lithium can give a metallic taste. When someone is allergic to a specific food, the food can often be detected even in extremely small amounts. Food allergies, such as with sulfur dioxide, can also cause this. Some gastrointestinal disorders can be aggravated by food allergies and cause burping, dry mouth, thirst, rectal itching and a metal taste. High protein diets can cause benign dietary ketosis. This has also been associated with a metal taste.
Chemotherapy, radiation therapy or cancer can cause a metallic taste. It has also been associated with B 12 deficiency, zinc deficiency, Bell's palsy, Strep throat and Sjogren's disease along with things that cause dry mouth. If you would like to consult with our senior Georgia Dentist, Dr. Padolsky, call 404-874-7428.